Going down.....

[DonBattles]

My home sits on a slab foundation, any idea's on how I can do subs in the floor? From a structural standpoint I think I know what to do but my concern would be moisture Any idea's on how this could be solved? By the way I'm not working right now and way too much time on my hands....LOL

 

[jamie2112]

you may need this

 

[Hostility]

fiberglass?

 

[mjg100]

My home sits on a slab foundation, any idea's on how I can do subs in the floor? From a structural standpoint I think I know what to do but my concern would be moisture Any idea's on how this could be solved? By the way I'm not working right now and way too much time on my hands....LOL

If you are going below floor level, I would make the walls out of concrete and the front baffle out of wood. if you use concrete you will not require any bracing. I saw a thread on another site where a guy built his sub into his basement foundation when forming and pouring his walls. As far as moisture, just waterproof the inside of the box. To build this you would saw out the floor and pour the bottom. Have rebar stubbed out of the floor where the walls are going to be. Then form the walls and pour them.

You can do it all in one pour by building a wooden box (open top) and fitting it into the center of your (dug) hole. Then you pour concrete around the box. Vibrate well to get under the box. The box (form) will need to be braced well so that it does not flex or collapse when the concrete is placed. You will need to run 2x4's across the opening and attach to the box. These 2x4's will need to be bolted to the floor to hold the box in place (up lift) when pouring the concrete. Also keep in mind how you build the box form. You do need to be able to remove it. In other words do not build the bottom the full size of the formed box. let the sides extend down to the bottom of the form. This will allow you to wreck the form. I have formed and poured many elevator sump pits this way.