# Pour new larger slab on top of existing slab



## khansen46 (Sep 25, 2016)

I have a wood frame metal shop approximately 24'x24' on concrete slab. The slab is currently close to grade. I live south of Houston, and my yard has a heavy clay content. During heavy rain I sometimes get as much as 3" of water inside the shop. I know that I have drainage issues that need to be dealt with, but that will have limited results as the only place to channel the water is the front ditch which also fills up (we are out in the county). 

A concrete company came out yesterday and recommended we pour 6" of concrete on the existing floor. As far as the ceiling goes, I think I can deal with losing the 6" of head space. However, this causes issues with the overhead and entry doors, as I would have to cut into the headers on two sides to relocate the doors. For the amount of restructuring that will need to be done, and the overall condition of the shop, I think it may make sense to take down the shop and start over. 

Can I take down the shop, and have a new slap poured on top to the desired elevation while making it approximately twice the size? I'm thinking around 24'x50'. I would then have a new shop put up. The concrete company only offered the option of removing the old slab and starting over. 

The existing slab looks like it was poured after the framing, so the main posts (I think they are 8"x8") are in the concrete. I can't raise the shop independent of the slab. I've though about installing new framing around the bottom and cutting the posts flush with the concrete so it can be raised, but with that level of effort, and considering I want to make it larger anyway, I think I'd be better off going with a new shop altogether.

Any thoughts?


----------



## beachguy005 (Sep 25, 2016)

If you're even considering keeping the existing building and adding on to it, would it be worth considering pouring the 6" slab, abandoning the doors and build them into the new addition?


----------



## khansen46 (Sep 25, 2016)

The sides of the shop extend down past the side of the slab, so the new slab wouldn't actually connect to the old one. I could take down the one side, but it the side with the slope of the roof, so that would cause issues with the new part of the building.


----------



## beachguy005 (Sep 25, 2016)

How about leaving those doors at the existing level and ramp up to a new slab.  A 6" rise isn't much for a couple entry ramps and the rest of the space would be dry.


----------



## khansen46 (Sep 25, 2016)

This is a case of EITHER/OR for me. I can just fix the existing shop by raising the floor, or build a new one. Because of how the shop is positioned now, I can't just add on to it in the direction I need to go. If I were to do that, I would need to dismantle the roof and run the peak in a different direction. That, in turn, means pulling down all four sides and rotating them. By that time I think I'm better off taking the whole thing down. One other option is to leave this one as is and use it just for lawn equipment and such, and build a new one in a different location. I can do that, but don't want to have a bunch of buildings all over the property - I only have an acre. 

The more I think about it, the more I think I'm going to end up tearing it all down and starting over.


----------



## nealtw (Sep 25, 2016)

khansen46 said:


> This is a case of EITHER/OR for me. I can just fix the existing shop by raising the floor, or build a new one. Because of how the shop is positioned now, I can't just add on to it in the direction I need to go. If I were to do that, I would need to dismantle the roof and run the peak in a different direction. That, in turn, means pulling down all four sides and rotating them. By that time I think I'm better off taking the whole thing down. One other option is to leave this one as is and use it just for lawn equipment and such, and build a new one in a different location. I can do that, but don't want to have a bunch of buildings all over the property - I only have an acre.
> 
> The more I think about it, the more I think I'm going to end up tearing it all down and starting over.



Most time the beam over the door has 2 wall plates above it and 1 door sill below so you can raise it three inches and do away with the sill and you have gained 4 1/2"  Post a photo from the inside.

To add to the side of the building, open 2 10 ft opening and install headers. 
Cut there tails off the rafters flush with the outside of the wall,build your addition and install trusses and a valley set that goes up on the old roof to extend the new peak over to the old peak.

Ist thing you do is jack up one wall at a time cut the bottom of the wall and raise the foundation with cmu blocks.

When you do the slab, 2" of sand and then 4" slab 6" around the edges.

see valley set
http://hitec.ca/trusses.html


----------

