slab is larger than moved garage…
About 20 years ago, i wanted to move an existing 1 1/2 car 1938 garage to another section of our lot & use it as a wood shop, at the time, i wasn’t real concerned after we moved the building, about the slab (my 1st ever attempt @ forming & pouring a slab) being larger in areas than the garage. i used left over rubber roofing membrane as “flashing”, up the exterior wall, underneath the bottom course of cedar lap siding 6 inches or so & flapping over the slab, the rubber even held paint for many years. Looked kind of tacky, but the building is sort of out of site. Presently, i am replacing the cedar with Smartsiding & wondering how to address the slab issue properly. Watertable trim? lead flashing? any ideas & feedback would be appreciated. Starting the project in the next few days, have some unexpected time off due to the virus thing. thanks in advance!
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One technique I've used to address this same situation is to run a circular saw fitted with a masonry blade around the perimeter of the building. This creates a kerf in the slab 1 1/2 inches away from the building. You can cut the kerf at whatever depth you want, but I've done 1/2 inch. This allows you to install a z-flashing on the face of the sheathing, out the 1 1/2 inches, and down into the kerf in the slab. Fill the kerf with sealant before dropping the flashing in and it's basically waterproof. You can have the vertical leg on the building as tall as you want, so you can hold your siding up a couple inches off the slab.
That's always going to be an issue. I'd rent a concrete cutoff saw and a diamond blade and cut the excess off. No good ever comes from having the concrete larger than the building.
ya i thought about doing that too... today i noticed in the install instructions that they want the smart siding 6in off the grade/ground, which the old siding is not that hi, was about 3 inches, so it led me to think i may run a 1- 1.5 in thick x 3in wood or pvc board around the bottom with a flashing & then start the bottom coarse. Wondering what wood to use if PVC is too expensive. Thanks again...
that is interesting, but the "reveal" is not consistent around the building. today i noticed in the install instructions that they want the smart siding 6in off the grade/ground, which the old siding is not that hi, was about 3 inches, so it led me to think i may run a 1- 1.5 in thick x 3in wood or pvc board around the bottom with a flashing & then start the bottom coarse. Wondering what wood to use if PVC is too expensive. Thanks again...
I always run a Pvc 1 X 8" or 1 X 12" on the bottom to keep the siding away from the ground.
Are there no footings?
no footings, why do you ask?
A building without footings is a problem waiting to happen. How is it secured to the slab?
If you don't care. Follow Florida's advise and cut off the excess concrete.
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Unless you are moving the building again, I think cutting the concrete flush or set back from structure will be hard to do. Unless you higher out expensive concrete cutting contractor w/ specialized equipment. Simplest most affordable option that will work if done properly is to do what John suggest. We do this on just about every commercial storefront remodel where cladding materials are designed tight (ish) to the slab. It does require custom flashing to be bent. The flashing is simply an oversized Z flashing. For a simple residential garage can probably use a siding brake with thicker coil stock. On commercial applications thicker gauge material is used, so we out source bending to a metal shop. Need to cut the joint in concrete at least an 1” deep to keep flashing in place. Also, very important that the flashing pitches away from the building. Sometimes creating a slope with mortar for flashing to sit on is required (doesn’t take much). So we cut the slab first (6” min) from structure. Install 12” peel and stick waterproof membrane tight to slab up the structure. Mortar a slope on top of slab between the cut and structure. Apply really heavy duty commercial grade sealant with continuous thick bead at cut. Place flashing on top of that. Can leave your siding up 6” and have exposed flashing below that which can be painted to match siding.
And as Mike was saying. It isn’t really code approved to sit on a slab. If you have a monolithic thickened edge slab it might be, depending upon your local code authority. I would imagine a garage built in ‘38 doesn’t meet any modern codes anyways.
jlyda you give sound advice and it sounds like you have good experience, but why do you think that cutting of the slab would be that difficult? A laborer (or homeowner) with a gas powered demo saw should be able to do it. Follow up with a chipping gun if the demo saw doesn't make it all the way through the slab.
It's probably less work than making up the custom Z flashing, kerf joint, peel and stick , caulk and mortared slope,
The only way that I no how to make a flush cut to line up with garage walls is to use a special flush cutting saw that only concrete cutting companies have. With a standard circular saw you can get close, but are still 1 1/2” away. The whole idea is to get water to drain straight down the wall plane. If that is not possible, proper flashing is required. If a clean cut is not of concern can try to get a cut off saw in there and chip away, but it won’t look very finished.
https://www.youtube.com/watch?v=ZKV63kXYtx4. Here you go, this is exactly what we do. Works like a charm but have to use a high performance sealant.
The sealant needs to be a hydrophilic type. It’s expands with water, worth the cost.