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[hondaracer2oo4]

Good morning. I am getting ready to frame my garage up and wanted to bounce a question off you guys. So the Garage has a full frost wall foundation so the frost walls sit 6-9 inches above the floor slab(pitched 3 inches over the 28 feet towards the doors). My question is about the PT sill plate. The frost walls have J bolts 1 foot in on the corners and every six feet on the walls. The j bolts stick up about 2.5 inches. I plan to lay a PT sill down but my question is should I do a double bottom plate? PT sill first bolted down then wall assembly with a KD bottom plate/shoe somehow attached down to the PT sill when it is stood up? Or should I just go with a PT bottom plate/sill in one? I would like to put a PT sill down first and bolt it down making sure everything is all squared up first and then plate a wall assembly on top but I am hesitant because I would need to drill out the holes for the KD bottom plate to slip over the j bolts holding down the PT sill and then I would have to somehow attach the wall to the sill. Any suggestions would be great!

[MerrellRoofing]

I would double bottom plate. Just mark and drill your 2nd bottom plate before you put the wall together.

[hondaracer2oo4]

Any particular reason for it?

[hondaracer2oo4]

And how would you connect the pt sill to the bottom plate?

[Pointblank]

Maybe check with your local building official, as codes can vary wildly from state to state,  but we've always singled plated the bottom of our walls. Once you square the building in and snap chalk lines its fairly easy to measure out and accurately drill the holes. If its a 1\2" anchor bolt,  we drill a 3/4" hole. That usually gives you enough room to tap the wall in or out a bit to flush it up with the chalk line so your wall stays straight

As far as double plating, if you go that route, Id first lay down the PT sill plate and bolt it down into place.  Then build the wall like normal and simply nail it down to the PT sill when you stand it. Remember to drill the holes larger then you did for the sill as you now have nuts on the anchor bolts to go over.

[hondaracer2oo4]

I would like to go the route of the double bottom plate for a few reasons. One is after I square up and snap the lines and drop the pt sill on all I have to do is drop the wall on top of that. Second reason is I don't have to buy a box of 80 dollar galvanized nails for the gun just for attaching the pt sill to the studs. My question about attaching the walls down to the pt sill is doesn't just nailing the kd bottom plate to the pt sill defeat the purpose of bolting everything down to the frost walls? Nailing it down doesn't provide much resistance to pulling out in the case of a wind event which I believe is the purpose of bolting it down?

[MerrellRoofing]

I like the idea of using PT to get everything set and square. Use galvy screws to fasten your wall down to the PT.  Plywood will hold it all together anyway. A box of screws and a couple bottom plates, extra cost, but will be nice to be able to build the wall and stand it up.

[Pointblank]

You can always use construction adhesive between the plates if your worried about seperation. Once that sets up you usually tear wood apart trying to get it apart. But I guess your still gonna be buying some galvanized nails/screws to hold them together.  Either way, If wind damage is a concern, you can use hurricane ties. These are metal straps you nail along the stud that physically tie the stud down to the sill plate. Been to a number of storm damaged homes and if the anchor bolts held, the wall often fails where the stud is nailed to the bottom plate.

[hondaracer2oo4]

Well I went ahead and bolted down the pt sill today after squaring up the foundation with chaulk lines. The sides were equal length but the diagnols were out 1/2 inch from each. After I squared it and bolted down the sills I rechecked and am now dead nuts perfect. I plan to countersink holes in the under side of the kd shoes and then screw down the shoe to the pt sill with Coated screws. Now that everything is square it will be easy to just line up the wall on the sill.

[hondaracer2oo4]

On another note. I have a little variation on the height of the sill when I run a string across the length of the wall. Sill height changes about 3/8 of an inch at the most. Should I just pin down the ends of the sill that aren't near a bolt( concrete guy put the j bolts 1 foot in from each corner then every six feet but that doesn't account for boards ending and always having a bolt within a foot of each board end, I can Ramset them down) Then should I just shim the wall bottom plate to accommodate any variation? I plan to screw the wall down to the pt sill so that should be fairly easy to adjust.

[coolidge]

That's how I did mine, use cedar the moisture in the PT will rot the regular shims( so I was told)

[hondaracer2oo4]

How did you find level of the wall top plate all the way around? I have a laser level but it's really not bright enough for outdoor use over those distances.

[Cabo]

Can you set your laser in the middle of the garage and shoot the 4 corners?  If so, shim your corners so they are all level, build your walls, stand them up and use a string line to shim/straighten.  It is easier if you put a scrap 2X block under the string so you can shim it to 1 1/2".  You can shim either the PT plate this way or shim between the PT and bottom plate of the wall.  Any gaps can be filled with a good caulking/silicone so that you don't have any air infiltration.  Hope this helps.

[Pointblank]

Is the variation in height coming from the concrete or is it your sill plate just bowing up?  If the concrete is straight, I'd be hesitant to shim at this point. Once you get the weight of the walls and roof on it it should flatten out and conform to the concrete. If the variation is in the concrete, then ya,  you'll need to shim.

[hondaracer2oo4]

I think the variation all comes from the pt sill bowing in certain spots. The concrete guy used his transit level and marked all around the forms with finish nails at the correct Hieght then poured and troweled it to those finish nails. Probably just call it good and let the weight of the building pin it down.