Slipforming, part 14 – Cold seam repair

This post follows Slipforming, part 13 – Kitty’s take on it.  To see a complete index of slipforming posts, click here.  For an index of comical posts, click here.

If you have gotten this far in my posts, you have read about how to slipform, what the concrete looks like fresh out of the forms, how to scrape it off for a smooth joint and the dangers of using mixed sources of cement.  An area that I have not covered is how to repair cold seams.  Cold seams are the bane of a concrete slinger’s existence.  They are deceptive.  They are not forthright, they make promises they do not keep.  They should die.  And now I’ll tell you how I really feel.

Kitty, Dad and I were racing an unforgiving clock–Colorado weather.  We knew we would get done only what the weather would allow.  As luck had it, we had glorious weather until one week before Thanksgiving.  That was remarkable because often we have snow by Halloween, which is in late October for those of you reading this from other countries.  We decided to go to the nine foot mark because that would be where the second floor would be attached to the slipformed walls.  

I read material on Helen and Scott Nearing and how they suggested to leave exposed rock sticking out atop the cement for the next layer of cement to bond to.  (This photo, at right, is of our shed, so disregard the wire mesh and focus on the rock tops that I leave exposed.  Leaving a layer of rock exposed allows the next pouring of cement to grab onto those rocks and also allows a normal seam across the top edge of the rocks.  The downside is that when you leave rocks like this exposed over a winter, snow and rain can occasionally get behind the rocks and pop them from the wall.  Left for a season, the break in cement causes a cold seam where the old concrete has cured and the new concrete continues to cure at a different rate, thus encouraging cracking.)

Also, it is important to leave rebar exposed so that the new concrete has something to grip.  I did that.  The cement was left to cure from September until the next spring.  Snow fell.  Spring rains washed the walls leaving small puddles that froze at night in the crevaces of cement.  In at least one area, the rain got in valleys between the exposed rock and the level cement and popped the seal of the exposed rocks.  This, I was not to discover until this year – a full 10 years after pouring the initial cement.

For those of you wondering why it would take 10 years to discover a cement problem, this comes my accusation that cement lies.  When I first poured the second layers of cement, there was no indication that I was going to face any cold seam issues.  That came later, first with a hint of a problem.  A hairline crack barely visible to the naked eye.  Being an optimist, I hoped it was just settling.  Then, it grew to a wider crack.  As it grew, I worried.  Was the house settling?  Should I repair it immediately?  Should I wait until all settling stopped?  Was something structural going on?  

My decision was to wait and allow any settling to occur, then to repair the cold seam rather than repair it every year.  The cracking did slow, and now at 10 years, I believe it has stopped.  That made this the time for repair.  Now, others might advise differently.  Certainly, weather is a consideration and can complicate repairs.  If your winters are harsh, with a lot of moisture, you may want to seek other opinions.  Our winters are not that harsh, and there is less rainfall in our county than in Tucson, Arizona so I was not that worried.  The big issue is having water enter those gaps, freeze, and weaken the wall.  To avoid that, grouting helps considerably.

Filling the gaps with caulk, or with mortar glue before applying grout is one possibility.  Applying straight grout into the gaps works, too.  This photo at left shows glue applied in the crevaces around the rocks.  From here, grout will be applied over the top hiding any sign of the glue and giving a uniform appearance. 

Our cold seam repair is somewhat of an experiment, which I hope to update next year.  We chose to repair our cold seam with masonry glue, which is applied like caulking.  Then, over the top of that, we put a mortar mix of straight mortar mix and water.  We mixed a stiff batch adding only enough water to bind it, but not so much that it was soupy.  Before applying the grout, we washed the walls and wet them down.  This keeps the dry cement from absorbing the moisture in the mortar mix and weakening the grout. 

The photo above shows a grouting job in process.  Notice the rough edges of the ungrouted cement.  These rough edges work really well because the jagged edges allow the freshly applied grout to grip the surface.  When the entire surface is complete, the joints will all be smooth.  This will repel rain, snow, insects, small children and Ken’s secret notes.  (Just kidding.)

It goes without saying that one must remove all loose rocks, cement, or dirt before applying the grout.  Make repairs carefully and then the grout can be molded into place by hand.  We used a small pointed trowel, but often we only used it to transport small handfuls of cement to the gaps.  Then, we used our gloved hands to work the cement into the gaps.  Dragging a finger atop the grout leaves a smooth grout seam.  That is what you want.  Rough edges catch water. The water, in most cooler climates, freezes and it is that freezing process that is the cause of most problems.

Most people who have experience with cement advise to grout as soon as possible after installing the cement.  I agree.  The bond is easier to encourage.  We have more than one project and have handled them differently.  The new shed was grouted as it was poured.  The house was grouted 10 years after it was poured.  While it is preferable to do it early, it is better to get it up late than never.  Grouting protects your work and your investment. 

Now, with vertical cold seams, the cracks are sometimes more problematic.  This one is a cold seam in a raised garden wall.  It was made worse because of tree root growth which ran beneath the wall.  The gap grew as winter snow and rainfall froze inside, further spreading the crack despite rebar extensions from the sides of the cement.  To repair this gap, Ken filled it with expandable insulation, then will shave off the extra insulation and grout from there.  Extra foam can be removed with a muriatic acid/water mix when it is smeared across the surface, but the acid will eat the foam quickly, so applying it to the actual joint is not recommended, as it will eat the foam you intended to stay in place.

This crack can be covered with grout without a problem.  We completed a similar vertical crack a few feet away from this one a few years ago and it has given us no problems, nor did it continue to crack.

Final word on cold seams:  An ounce of prevention is worth a pound of cure.  If you can pour your project consistently without long gaps between stages, you will have less cold seam problems.  If, like us, you cannot finish the project in one season, then you will likely face cold seam cracks.  Fear not.  They are not that difficult to repair, but do not delay.  The sooner you repair them, the less damage future weather will have on your walls.

(See Slipforming, part 15 – Snow and the balcony for the next thread.) 

Slipforming, part 13 – Kitty’s take on it

The following post is a guest post from my dear friend Kitty, who constituted one-third of the initial work “crew.”  This post follows Slipforming, part 12 – Repairing masonry blunders.  To see a complete index of slipforming posts, click here.  For an index of comical posts, click here.

First let me start by saying I have known Dani since high school. I was not all that surprised when she said she was going to build a house.  In many ways it is so “Dani.”

When we first met on the site we went into a little camp trailer where she enthusiastically showed me a copy of “Mother Earth” magazine and outlined the project to me. I had a hard time grasping that we were going to use these Styrofoam panel things and later do rock work. I was available to help Dani in the mornings because my middle son David was going to a nearby preschool. I neglected to tell her I was pregnant with my third child.  My husband and I had not broke the news to anyone yet.

Even though I could not grasp the entire project, I signed on to help explaining to Dani I was a little confused but could certainly follow directions and be a good grunt. The footers had been poured and you could tell where the windows and door were going to be. I painted many a panel with linseed oil as Dani mentions in a prior post.

When I saw my first panel I wondered, “How many Styrofoam cups did somebody mash to make this thing?” I remember asking and needing reassurance, “These are going to be the walls – we are going to lay the rock directly against these – the same with the interior- the sheet rock will go up against this?” Quite frankly I had my doubts. I thought the panels would break or shift.

I was the Martha Stewart of the work crew.  What a crew – her dad, Dani and myself. I’m sure when people drove by they thought, “What the hell are those three doing?” Dani was forever misplacing things like her pliers, the wire, etc. So, my plan was to put everything in the wheelbarrow when not in use. Dani, why didn’t we have tool belts? So a conversation might go something like this:

Dani: Kitty we are ready to pull the wire through the panel.  Have you seen my pliers?

Kitty: No, have you checked the wheelbarrow?

Dani: They’re not there. Don’t start Martha; I know if I had put them there I’d be able to find them.

DG adds comment:  Kitty was right.  My brain was running 200 mph, and often I’d be thinking about a step five steps ahead before realizing I had set down the pliers in an “unapproved” place.  My disorganization was definitely a thorn in everyone’s side.  Kitty was particularly good hearted at reminding without nagging – a skill she possesses that no one else can seem to duplicate.

I remember the day we set our first rock. Her dad and I (I’m 46 years old and don’t know whether to call the man Mr. Lemoine or Bill!) Anyway, we tried to talk her into just going three foot high or so with the rock all the way around so if problems were encountered she could adapt her plan and finish the house as a stick build. But nooo- we did our first slip forms and the next day the second until we had committed ourselves to 12 feet high, I believe. I was thinking Dani should be committed!  DG:  It was nine feet high – it just seemed like 12 feet!

One has to picture the scene to truly appreciate this wonderful house. We worked on makeshift scaffolding constructed from railroad ties and wobbled our way around.  Later, after I was off the project, Dani got “real” scaffolding.  (DG:  But Kitty, admit it, childbirth was sooo much easier having carted around railroad ties for the first seven months of pregnancy, no?)

We poured cement from coffee cans. I was the runner, giving Dani coffee cans of cement and additional rocks when necessary. Dani would dump the can then holler, “I need another rock bigger than a softball but not as big as a cantaloupe.” Her dad would ask, “How many shovels full of sand did I put in that last batch? It was a nice consistency.” Surely we looked like the three stooges at times. And, what a sport her dad was. I think he found great humor in it all. He mixed cement faithfully never questioning our methods to my memory.

My days ended as I was now beginning to show, I finally confessed my pregnancy. Dani was shutting things down for the winter also. I am proud and honored to have worked on this house with Dani. I drive by the house with friends and relatives and boast, “I helped build that house.” Keep in mind we had young kids that helped us gather rock – my two boys and Dani with Heidi and Ben it was quite a sight to behold. It was a wonderful adventure with lively conversation with such topics as what animated cartoon character would you like to be? Or, true heart-to-heart talks – the things girlfriends discuss. I now enjoy cups of tea at Dani’s kitchen counter in the wonderful house that Dani built.

(See Slipforming, part 14 – Cold seam repair for the next post in this series.)

Slipforming, part 8 – Successes and failures

This post follows “Slipforming, part 7 – Murphy’s Law, a constant companion.”  For a complete list of links to all slipforming posts on this blog, click here.

Any time one tries something brand new, it is unreasonable to expect only glowing success, but I did anyway.  Bolstered by the fact that I had read every article I could lay my hands upon, I was, after all, an expert.  (Heavy sarcasm here.)  Of course, the laws of the universe always have some humility lessons to offer.  And my rock laying was no different. 

I had (mostly) overcome doubt, hand pain, gravel quarry funny-men loading my truck to near un-drive-ability, and the lack of bathrooms.  I had successfully built some outstanding forms, and even layed my first rocks in cement.  The problem?  Well, I really had no idea how close to set the rocks to each other.  Tom Elpel mentioned in his book that one should grout the joints at some later point.  I went to neighboring rock buildings in the area, probably done a hundred years ago by masons who actually knew what they were doing, and they had small joints less than an inch in width.  The only way I could figure to achieve that end was to mash the rocks up very close to each other and then grout over the gaps.  That is probably one way to do it.  Fortunately, that is not the only way, and with hindsight, I do not believe it is the best way.  For our project, as I progressed, I got “looser” with the rocks.  I would leave bigger gaps between them and found that the result, to me, was both more eye-pleasing and much easier to clean. 

I want to note here – slipforming is different than stone masonry – with stone masonry, the strength of the wall is inherent in how the rocks rest atop one another and a great deal of skill, patience and forethought is necessary for the strength of the wall to stay in tact.  With slipforming, you are actually using the cement/rebar portion of the wall for the strength and using the rocks only as facing.  The home is not dependent on the rock setting for the entire load of structural strength.  This difference allows a novice, like me, to enjoy the stone home ”look” without having to spend years as an understudy to a genuine mason.  Secondly, much of the work is done blindly, i.e., one cannot see the rocks beneath cement to adequately assess if the new rocks are bridging gaps between rocks, or not. 

A fundamental lesson was determining how long to leave the forms in place.  Dad and I were eager to pull the first forms, to see the results.   After much waffling, we decided to leave the forms in place for six hours.  Wow!  We were stunned.  The relief, compounded by sheer joy, was palpable.  The “look” we were hoping for was there, all right.  What a relief! 

Here, a rare photo of Dad and I immediately after pulling forms off the rock wall.  If you look closely, you will see the small white chunks of foam in the photo.  These worked wonderfully as gap-fillers and reduced cleaning and spilled cement substantially. 

My husband Ken and I chipped out the unwanted cement and gloated over how beautiful the rock work looked.  Building on one another’s thrill, we quickly went from “Wow, it worked,” to “This was easy!” to “We could do this professionally!”  Then, we realized we needed to do it again, and our cockiness dissolved.  Could we?  Of course.  In fact, I thought we could do it with even less curing time.  

The next day, we tried three hours of cure time.  Oh my!  Three hours was not enough.  The rocks were not sufficiently adhered and quickly, a rock came tumbling out of the wall.  As I have mentioned, this has only happened about four times in the entire house, but this one was depressing since it was the first one to fall out, and I had no idea how to repair the problem. 

A quick phone call to my ex-boyfriend’s mother (the same one that helped me with the hand pain) eased my concerns.  “Oh honey,” she said.  “You just go buy some rock glue.  It’s at the lumber yard – they’ll have it.  It’s gray and you’ll frost (woman-t0-woman instruction coming back to cake decorating) the back of the rock.  If the cement on the wall is still soft, chip out a little more room so that your rock will not stick out too far.  Otherwise, this will work.”  She was right.  It did.

I got more guffaws when I went to the lumber store seeking rock glue.  It’s understandably not a big seller.  A couple of contractors ribbed me saying that if THEY were building my house, they wouldn’t be resorting to glue already!  At any rate, the pain of the experience was sufficient that I did NOT want to duplicate this error.  Toward that end, I thought we could make a thicker mix of cement.  The cement thus far had been fairly soupy, meaning it would pour out of the coffee can without much trouble.  I thought a little thicker cement mixture might be better, so the next day Dad mixed a thicker batch and I got sidetracked that afternoon with other important stuff.  The cement cured for nearly 10 hours.  Oh boy!  What a difference the added time and thicker consistency made. 

Ken and I each had a hammer and were pounding away at the excess cement on the seams, sometimes with not much success.  Sparks were flying from the ends of the hammers.  Our arms were exhausted.  “What did you leave it this long for?” he asked.  “Good grief, we’ll NEVER get this off!”  The seams were choppy and crude.  Any overconfidence I had gained from the first day was dashed by day two and then compounded on day three.  But, I had learned a very important lesson:  Consistency is a virtue in cement work.  Make the batches of cement the same way, leave them for the same amount of time, and you can expect a similar end result.  Do it any different, and you will be your own worst enemy.  With hindsight, four hours is a nice amount of time in moderately warm weather to let the cement cure. 

My lessons were not limited to cement.  I was pouring cement on one side of the house while still setting up the foam panels on the rest of the walls.  I had this great tool, a chalk line dispenser, which I thought was a wonderful invention.  Men reading this will wonder why I was so impressed with the chalk line, but in a woman’s world there is no need for such a tool.  You don’t use one to bake, sew, or clean.  You don’t need one to balance a checkbook, or get the family pets to the vet and you can get a child from kindergarten through graduation without EVER needing one.  Consequently, I adored my chalk line with it’s little pop-out lever for reeling the string back inside…until I ran it over with the truck.   

This was, indeed, unfortunate.  I grieved.  Knowing I could not continue my life without another, I bought a replacement and returned to the work site where I did not need it again until one afternoon while I was killing time awaiting the visit from a windshield repairman.  As I was waiting, I had extended the chalk line out to mark a foam panel for the next saw cut, and found, much to my horror, that this chalk line did not have a pop out lever to reel in the string.  I sat there, staring at the chalk line, cursing the fact that the string was now extended and I could not get it back inside when the repairman drove up. 

He fixed the windshield quickly enough and then saw me diddling with the chalk line and asked what the problem was.  I explained that this stupid chalk line was already broken and ranted that things today are certainly not made like they used to be, as this chalk line didn’t even have a lever!  What was it, I asked, a single-use chalk line?  Intrigued, he asked me to hand it to him.  Inserting his index finger into the circular inset finger hole, he effortlessly dialed the string back into the chalk line.  Boy, did I feel stupid!  And, boy did he get a big laugh out of it!  He was my mother’s cousin, so you can probably imagine how discreet he was with this finding.  (Not!)   He wondered what bank in their right mind would loan funds to a house builder who could not operate a chalk line.  He laughed even harder when I said that I had not borrowed on the project yet. 

He continued to laugh as he jumped into his truck and laughed the entire way back down the driveway.   It is a good thing I have a thick skin, or else that exchange might have shaken my confidence in attempting a house like this.  Instead, it fired me up to prove that even I, who could not figure out a stupid chalk line, could overcome absurd obstacles if I wanted to bad enough.

It is important to mention that with each setback, growth occurred.  As humiliating as it is to realize you are being stupid – it is equally heartening to find that there is one less area where you will ever be stupid again.   Though sometimes, that is an admittedly hollow comfort, especially from ground floor of a project like this one offering so MANY opportunities for embarrassment.

To see “Slipforming, part 9 – Some cool rock inspirations,” click here.

Slipforming, part 7 – Murphy’s Law, a constant companion

This post follows “Slipforming, part 6 – The latest project.”    For a complete list of links to all slipforming posts on this blog, click here.

So, we’ve covered that my biggest hurdle was overcoming doubt. Then, everything around me began to die, and then Dad’s added his initial view of the project admitting that he was not proud to confess that the entire work crew consisted of one 73-year-old man and two women in their early 30s (one pregnant, but thankfully not me). Out of this amazing work crew, none had built a home before. What was he thinking? (He was thinking it would last one week. That’s what he was thinking!) Happily for me, disappointingly for my father, I did not quit after one week.

We had dealt with the ugly reality that we were building a home without a plan – justifying this decision because I’d never built a home before, and didn’t know if it would be one floor or two, mindful of the ever-present possibility that I might beg to quit mid-way through the project. We needed flexibility, and that was solved by just not putting the floor in.

What would not putting in a floor have to do with it?

Well, by stubbing the water, gas and electric under the foundation, and leaving them inside, we could run them anywhere we chose. That decision freed me up to continue working on the rock walls while the weather was nice, and during the winter months I could obsess over where everything would go. I am quite aware this is not an ideal situation, nor am I advising it, but it was the only solution that fit our needs. Ken wanted in-floor heat and that decision required a more serious knowledge of the layout, which was dependent on knowing if we could add a second floor.

I knew where the kitchen, dining room and living room would be positioned, so we focused on what we had, and postponed what we did not. Toward that end, I began gathering rocks and we focused on putting up the exterior walls which took the bulk of that fall. I was very lucky, we did not have rain or snow until one week before Thanksgiving, an unusual year that blessed my project!

One thing I had not counted on was that I got in better shape lifting those rocks. Dad maintained they would get heavier with time, but in reality, they got lighter. By the end of four months of moving stones (and our make-shift scaffolding) around, I probably could have arm wrestled a high school boy and won!

I was lifting, moving, re-lifting, re-moving rocks almost all day. When I was not moving rocks, I was lifting the foam panels, lumber and tools. It was a very good workout. Very thorough! I slept very well every night from all the activity.

I also discovered that Murphy’s Law was alive and well. At this stage in the project, I learned three of Murphy’s Laws intimately:

Murphy’s Law #1: Early on, though I was only carrying cement in small coffee cans, I was lifting a lot of rocks. I was surprised when my hands started going numb, particularly in the fingers. As I would grasp the rocks with my fingers, spasms would shoot up my arm that were similar to electrical shocks.  It was the same feeling as hitting the funny bone on your elbow, except it was in my finger joints and ran all the way up to my shoulder. They were painful and this concerned me. Those who knew I was suffering suggested it might be carpal tunnel syndrome and that it could require surgery. That was an unacceptable answer. How could I finish this darned project if my hands quit on me within the first three weeks?

Luckily, a friend of mine – the mother of my high school boyfriend – came to the rescue. She was a rock hound who had spent the last 40 years of her life lifting and carrying heavy rocks. I asked her if she had ever had such problems. “Well, honey, of course!” she said in her high-pitched voice, laughing, “You’ve got to know when to stop. You need to take a break and let your muscles heal. I’ve had that happen hundreds of times. I just take some time off and it’s fine. Give yourself a couple weeks,” she said.

A couple weeks? But I was in September, with Colorado weather threatening to shut me down at any given point. Two weeks would seriously compromise my progress. I satisfied myself with a few days and spent those collecting other essentials for the project, namely 98-pound bags of cement and truck-loads of sand, which also provided some very important discoveries.

Murphy’s Law #2: Though I always considered myself an aficionado of playground equipment, I inadvertently ignored the hazards of duplicating a teeter-totter with a Ford pickup. For those fuzzy on teeter-totters and their application in slipforming, I discovered that 1) the gravel yard employees will let you put way too much sand in your truck; 2) when you load an old Ford pickup too full of sand – it tips the front of the truck upward, very much like a teeter totter, making steering an adventure; and 3) the gravel employee will think this is funny.

I had insisted on a truck full of sand – not wanting to make unnecessary trips back for more, and the bobcat operator looked at me and grinned. I think he knew it was a mistake I would make only once. And it was. I rolled out of the gravel yard driving like a drunken driver, swerving to the right, then over-correcting to the left. My maximum speed on the way home was probably 10 miles an hour and I was praying for my tires not to pop. Of course, Dad took one look at the rig and asked me what the heck I was doing to his old truck? Did I want to die? At that moment, the answer was “Yes!  Please!”

Murphy’s Law #3: On any building site, the likelihood of having to use a restroom is inversely proportional to the availability of one. In other words, if you need one, you won’t have one, and if you have one, you won’t need one. Secondly, your desire to “go” always seems to occur just moments before someone important drives up, regardless of the fact that no one has stopped by the site all day. Thirdly, these people are snapping photos as they approach the place, of course assuring you they will destroy any they might have snapped of you! (yeah, right…)

Ugh! I realized these facts early, and considered renting a port-a-potty. They are more expensive than I imagined, and as you will recall, I did not have a lot of money. That said, it made more sense to purchase a small camper and park it on the site, than to rent a port-a-potty. This decision had the added benefit of allowing me to get out of a rain storm, and provided a make-shift office and lockable tool storage. It also provided a spot for a kid (or me) to take a nap or wash a wound and apply a band-aid, if necessary. It was a brilliant decision.

That camper paid for itself over and over – and when I was done with it, I sold it for the same price I bought it for, thereby costing me nothing. It also had a working refrigerator and a stove, so when I was particularly depressed, I could dart inside for a hot cup of tea, or cocoa and regroup. Later, when I hired the roofing done and was paying by the hour, I suspected the roof contractor was fibbing on his hours, assuring me he was arriving one or two hours before I arrived. I started spending the night in the camper and my costs, and progress, improved markedly. All in all, that camper was a winner of an idea, and I still miss being able to just get away sometimes.

To see “Slipforming, part 8 – successes and failures,” click here.

Slipforming, part 6 – The latest rock project

This post follows “Slipforming, part 5 – Dad’s initial view.”  For a complete list of links to all slipforming posts on this blog, click here.

Whenever cement was delivered for sidewalks, or a stairway, it always seems that there was cement left over.  In one case, the cement company had a full yard of extra cement that they would give me, if I could take it.  Of course I would take it, I said.  This meant quickly slapping together forms in a variety of places where cement would not be a regrettable addition.  Consequently, I ended up with an odd extra outbuilding that had cement walls around the exterior up to approximately five foot high.  The walls were ugly, as we were in a hurry to pour the cement and always had the other “original” project, which needed finishing with fresh cement, too.  No problem, I thought, I’ll just cover it with rock later. 

Well, later has arrived.  This spring, we had MRA Construction put a roof on the building and I am very, very pleased with it.  Milan, the owner, was also my drum instructor in high school, so he knew what to expect and was exceedingly patient as I explained that I wanted a special roof line.  We have double glass doors that view this shed, and I did not want to be looking out at an albatross every time I passed those doors.  The extra curve in the roof adds a whimsical detail that I am thrilled to see.  It was definitely worth the small bit of extra labor and materials.

So, with the roof completed, it was time to address the siding.  Ken suggested we try a different method of doing the rock work – namely by smoothing the joints of cement.  This is unlike the finishing technique I used on the main house.  On the main house, the joints are rough.  It’s not that I didn’t appreciate a more “polished” finish, it was that I had my plate full learning how to do the rockwork and anyone suggesting I not only learn it, but learn to do it beautifully on the very first project, would have been limping home…smarter for the experience. 

Ken, to his credit, was persistent.  He really, really, really wanted it to look good.  So, I opted to try smoothing the joints immediately after removal of the slip forms.  This proves to those of you trying this method that adding the extra finish is not only easy, but highly worth the extra trouble, because you will not have to revisit the joints later to grout them.

So, here’s the short sheet on this process.  1)  You pour the rock and cement in between the forms, with the rocks cinched up close to the leading edge, cement oozing behind and between the rocks.  2)  You leave the cement to cure for 4-5 hours (depending on the weather).  I’m talking about Rocky Mountain summers and falls.  I’m also talking about a medium-stiff batch of cement to begin with.  If you are pouring soup into the forms, it may take a little longer. 

3)  You remove the forms.  Your result will look very rough, like shown in this photo, at right.  Don’t panick.  At this point, you will scrape, with the back of a hammer, or with your husband’s new iPod (just kidding) the extra cement off the rocks. 

 4) You will leave a smooth joint that can then be left to finish curing.  You do not need to do anything else to this concrete if you are happy with the joints.  If they still appear rough, you can take a paint brush (a stiff one), add some water and paint over the joints. 

 When you finish, you will be left with joints that look beautiful and you will exclaim, “Wow!  That was easier than it looks!”

Out here, we are racing the weather.  It’s cooler each day as we approach winter.  I had high hopes of completing this shed before spring so that I can add a chicken pen to the north side of it and have fresh eggs soon.  I’m not sure that I will hit my marks on completion time.  I had counted on a teenage boy’s help.  That was my first mistake!  (Just kidding, again.  Ben has been a fine helper.  He’s just very busy in school, tennis, contemplating his navel,…you know, the hard life of being a teen. 

I keep telling him, this will be a GREAT skill to carry into his adult life.  He will be able to build his family a fabulous home with the knowledge he’s gained.  Instead, he’s still hoping to win the lottery and hire others to do such work.  Toward that end, I wish him luck.  It didn’t pan out for me and I ended up doing it myself.  But, if he can make it work, who am I to stop him?

Here’s a shot of Ben chipping off the unwanted cement.  The extra cement, which falls into his hands, is still wet enough to shove into gaps along the seams between the rocks.  The old saying, “Waste not, want not,” is true around here.  If you look below Ben, you will see the older, cured cement with the finished, smooth seams. 

Lastly, if you have the unfortunate experience of having any rocks pop out as you are removing the forms, don’t panick.  If it is just one rock, it can be re-glued into place using a masonry glue made for the purpose.  In all the rock work we have done, we have had less than three rocks pop out, and usually it was along the very top edge where I did not apply enough cement to adhere the rock into place.  Use the glue, replace the rock, let it cure properly and then mortar around it as usual.  *Save the rock that falls out.  It will fit the hole perfectly.  If you try to fit another rock, you might regret it later when the replacement sticks out of place and draws attention to your accident. 

Hope this helps on your wonderful projects!  I will try to post photos of the finished project once we have completed it, which does not look like it will be the fall of 2009!

To see “Slipforming, part 7 – “Murphy’s Law, a constant companion,” click here.