Formwork, the Saga Continues

Noel's back is feeling much better, so today we set out to do more work on the formwork. We are lining the front side of the formwork -- the part that will be visible when the walls are backfilled -- with EPDM to make a smooth surface. A couple of weeks ago I ordered a 10'x10' 45 mil pond liner, and today we got it out to line some forms.

Applying glue to the face of the sleds

The first step was to apple the glue. We're using a polyurethane construction adhesive, which may or may not the the right thing to use. Pagano's didn't have any EPDM adhesive at all, which surprised me.

Rolling out the adhesive

After applying the adhesive, I rolled it out with a hard roller to get a smooth surface of glue over the form.

Laying the EPDM over the form

Then I pulled the EPDM up and laid it out over the piece nice and even. This was not fussy at all, though EPDM is very flexible and wanted to slide around in the glue quite a bit.

Using a craft knife to cut the liner

I used an Xacto knife to trim the liner to the form. I suppose you could use something more construction-y, like a utility knife, but the Xacto is nice and sharp, easy to use, and did the job just fine. I'm kind of notorious for using art supplies to do construction work; I even rolled the EPDM smooth with a linocut ink roller.

Stacked up forms drying

As we finished the forms, we stacked them up to dry with weights on them. Because each sled fits a particular spot in the walls, we made a key diagram and labeled them before taking the walls apart to do this work.

By the time I finished the gluing, I was covered in construction adhesive. I need to remember to get a pot of hand cleaner the next time I'm at the store, because mere soap was not going to get that stuff off. I started by rubbing my hands on the driveway, then I realized I could pull weeds and it would help rub it off, which was a little more efficient. But while that made my hands not so sticky, it also basically glued dirt to my skin. Hand cleaner with pumice would be have been ideal.

Working on the back of the forms

Then we spent some time working on the back formwork. It's much simpler than the front, so we basically just had to line stuff up and nail it, and mostly it came out very nicely. This is the formwork partway done; we got all the back formwork on the small side, and up to the diagonal section on the large side finished today.

The jig for the columns

The last thing we worked on was the formwork for the columns at the corners, where we need formwork on two sides (the in-line columns only need forms in front). We made this jig so we could nail together the walers (those are the 2x4 supports along the outside surface of the forms that keep everything together when the weight of the concrete hits the wall).

Making the square walers

Those walers are very simple: just a pair of 2x4s nailed together at a right angle. And that was much easier with the jig.

Stacked up walers

We very quickly made ten sets, two each for five of the columns (two more outside columns will only have one set of walers each, but we didn't make those today).

Assembling the column forms

Then we were able to assemble the column forms very quickly, nailing on the plywood faces.

Finished column forms

We checked them against the rebar column shapes, and only one will need adjusting (basically untying the rebar and shoving it into place). These will nail into the sides of the sleds and the back formwork perfectly.

Overview at the end of the day

I haven't shown an overview of the site lately, have I?

Now we're letting the glue on the sleds dry overnight, and tomorrow we might be able to squeeze in some more work in between being social butterflies. We could probably have kept going today, but Noel was actually being sensible about not pushing himself too hard and doing further injury.

posted by ayse on 04/23/11


My goodness what a job. I am getting so excited to see the concrete poured and the final form revealed. I butchered 9 broilers today and was wallowing in self-pity for all my hard work and then I see what YOU accomplished. -laugh-

Brilliant with the pond liner - I would have skim coated the wall later but then I'm always ghettoing stuff that way. That probably would have led to cussing and wall flaking eventually.

Next time I do a big project I need to get you out here to make sure it gets done right. :)

The thing about skim coating the wall is that it would make me crazy trying to get it perfect, and I didn't want that. As for us coming to help you, sure, if you can handle a couple of months of dithering and plotting, then a month or so of bickering and exhausting work. :)

It is really starting to look great I can't wait for the finish it really adds so much to approach to home and lends the atmosphereof Victorian grandeur! Are those the roses in pots holding up O.K. They are really going full blast here in southeast Tx. soon it will be just too hot for them.

I must have missed something. Where is the liner? Is it on the inside of the set up frames? towards the house?

Great how-to. good job!

The liner is inside the forms, on the front side of the wall. When we get things installed and in place it will be more obvious.

Note: We're getting pummeled with spam comments, so I've turned off the ability to use any HTML or include any links for the time being. Email with any issues.

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