Replacement concrete garage floor, dowelled into foundation?

Niffumdutz · 02-09-2010, 06:27 AM

Hello. I am thinking about getting my garage floor replaced and my front concrete porch replaced by a contractor. I am getting a new driveway and it would be a good time to do it all at once. The old garage floor looks to be heaved up in the center and sunk around the outside. The front porch is sunk down by about 1", and is also cracked and it wouldn't work to mud jack it. We have expansive (bentonite) soils around here, south-west Denver area.

One contractor said that for the garage floor, in addition to doing prep work like compacted road base, he would dowel into the foundation to anchor the rebar. I am worried that doing that would put strain on the foundation. The house is on caissons.

Is it a good idea, or a bad idea, to anchor the garage floor with dowels into the house foundation? I know originally they were not put in that way. And if it would be good for the garage floor to be dowelled into the foundation, what about the front porch? Will proper prep work eliminate the slab movement?

Obviously, I care more about not compromising the house foundation than if the garage floor moves.

So, let me know what the consensus is on anchoring the garage floor rebar into the house foundation? Standard practice or bad idea? Thanks much.....

Just Bill · 02-09-2010, 06:50 AM

The porch floor should probably be pinned, since it moves with the house and foundation. Garage slabs are usually free floating.

itsreallyconc · 02-09-2010, 08:20 AM

ixnay on doweling the garage floor but porch depends on the home's footer const,,, that's why we have isolation jnt mtl -

we'd replace the garage floor's base mtl w/properly compacted granular but not much experience w/expansive so bow to others

Niffumdutz · 02-09-2010, 08:52 AM

Quote:

Originally Posted by itsreallyconc

ixnay on doweling the garage floor but porch depends on the home's footer const,,, that's why we have isolation jnt mtl -

we'd replace the garage floor's base mtl w/properly compacted granular but not much experience w/expansive so bow to others

The house isn't on footers, it's on caissons. Would that make a difference?

I am also thinking that the garage floor shouldn't be tied to the foundation, because it's bound to move some, even when prep'd right.
But wouldn't the porch also move? I have seen porches dowelled in and poured when the foundation is poured. This porch is about 8' x 16'.

Sonya_AFR · 02-19-2010, 01:42 PM

Hi, I work for Advanced Foundation Repair which is in Texas. I think your optimal solution is to tie the garage floor to the foundation and suspend the garage floor off of the ground. This can be done with a drilled pier or 2 under the garage floor and with carton forms. I hope this information helps! www.foundationrepairs.com

wnabcptrNH · 02-19-2010, 09:31 PM

Many garage floors I have ever seen are not tied in. That being said I prefer to tie them into the wall so you dont get heaving and sagging of the slab. Make sure they is rebar or WWM (welded wire mesh) in the concrete and be sure they contractor spaces it all up so its not sitting on the sub base.

02-09-2010, 06:27 AM	#1
Niffumdutz Newbie Join Date: Jan 2010 Location: Littleton, Co Posts: 7	Replacement concrete garage floor, dowelled into foundation? Hello. I am thinking about getting my garage floor replaced and my front concrete porch replaced by a contractor. I am getting a new driveway and it would be a good time to do it all at once. The old garage floor looks to be heaved up in the center and sunk around the outside. The front porch is sunk down by about 1", and is also cracked and it wouldn't work to mud jack it. We have expansive (bentonite) soils around here, south-west Denver area. One contractor said that for the garage floor, in addition to doing prep work like compacted road base, he would dowel into the foundation to anchor the rebar. I am worried that doing that would put strain on the foundation. The house is on caissons. Is it a good idea, or a bad idea, to anchor the garage floor with dowels into the house foundation? I know originally they were not put in that way. And if it would be good for the garage floor to be dowelled into the foundation, what about the front porch? Will proper prep work eliminate the slab movement? Obviously, I care more about not compromising the house foundation than if the garage floor moves. So, let me know what the consensus is on anchoring the garage floor rebar into the house foundation? Standard practice or bad idea? Thanks much.....

02-09-2010, 06:50 AM	#2
Just Bill Member Join Date: Dec 2008 Location: Wilmington, DE Posts: 3,098	Replacement concrete garage floor, dowelled into foundation? The porch floor should probably be pinned, since it moves with the house and foundation. Garage slabs are usually free floating.

02-09-2010, 08:20 AM	#3
itsreallyconc Member Join Date: Jun 2009 Location: north atlanta suburb Posts: 2,120	Replacement concrete garage floor, dowelled into foundation? ixnay on doweling the garage floor but porch depends on the home's footer const,,, that's why we have isolation jnt mtl - we'd replace the garage floor's base mtl w/properly compacted granular but not much experience w/expansive so bow to others

02-19-2010, 01:42 PM	#5
Sonya_AFR Newbie Join Date: Jan 2010 Location: TX Posts: 4	Replacement concrete garage floor, dowelled into foundation? Hi, I work for Advanced Foundation Repair which is in Texas. I think your optimal solution is to tie the garage floor to the foundation and suspend the garage floor off of the ground. This can be done with a drilled pier or 2 under the garage floor and with carton forms. I hope this information helps! www.foundationrepairs.com

02-19-2010, 09:31 PM	#6
wnabcptrNH Member Join Date: Jan 2010 Location: Boston, MA Posts: 275	Replacement concrete garage floor, dowelled into foundation? Many garage floors I have ever seen are not tied in. That being said I prefer to tie them into the wall so you dont get heaving and sagging of the slab. Make sure they is rebar or WWM (welded wire mesh) in the concrete and be sure they contractor spaces it all up so its not sitting on the sub base.

Replacement concrete garage floor, dowelled into foundation?