Can I Lower Floor into Crawlspace?

[BobbyK10002]

Have one room that was added on years ago which is 3 steps higher than the rest of the house. Opened up the subfloor and there is room to lower the floor in order to make it level with rest of the house but by Code can I do it? The Footing for the "Added" room is slightly lower than existing house. If I pour a 4" slab on top of the footing is that OK? Then up from slab frame double stud wall up from there (against cinder blocks) and then existing wall up to ceiling rafters. House is in Massachusetts. Footing is about 2 ft below grade

 

[fatboy]

Welcome to the forum BobbyK!

I am assuming you are the owner?

Are the blocks above exterior grade or below? If below, were the dampproofed, or waterproofed? Some jurisdictions don't require non-habitable below grade spaces to be treated for damp/water proofing, but now you would be making it part of the habitable space.

Also, if they are below grade, then the foundation wall is supporting the soil pressures inward, the existing floor system would most likely be resisting that pressure. If you remove that floor, what resists the inward soil pressure on the block foundation? Particularly if you have expansive soils.

Without a drawing/design, it is hard to say what else there could be, but for me, the the short answer is, I would contact a local registered design professional and have them take a look at it, might cost you a few hundred dollars, but in the long run save you time and money.

As the new day begins, others will chime in, maybe I am making to much out of it.

Good luck!

 

[BobbyK10002]

Welcome to the forum BobbyK!

I am assuming you are the owner?

Are the blocks above exterior grade or below? If below, were the dampproofed, or waterproofed? Some jurisdictions don't require non-habitable below grade spaces to be treated for damp/water proofing, but now you would be making it part of the habitable space.

Also, if they are below grade, then the foundation wall is supporting the soil pressures inward, the existing floor system would most likely be resisting that pressure. If you remove that floor, what resists the inward soil pressure on the block foundation? Particularly if you have expansive soils.

Without a drawing/design, it is hard to say what else there could be, but for me, the the short answer is, I would contact a local registered design professional and have them take a look at it, might cost you a few hundred dollars, but in the long run save you time and money.

As the new day begins, others will chime in, maybe I am making to much out of it.

Good luck!

Hi....Yes, it's actually my parents house and they have trouble with the stairs so I thought it'd be great if I could lower the floor and eliminate them.
- Waterproofed....I'm guessing it's not but I was actually planning to dig around the foundation, seal it and then add Rock Wool Boards to insulate it, followed by gravel and drainage system.
- Expansive soil....actually the yard is mostly ledge...so guessing not an issue but I get your point about the inward pressure....I'm thinking a full concrete slab would counter that.
However, yes getting pro to take a look is good idea....I just wanted to throw the idea out there first to make sure I wasn't completely insane
Thank you!

 

[fatboy]

"Expansive soil....actually the yard is mostly ledge...so guessing not an issue but I get your point about the inward pressure....I'm thinking a full concrete slab would counter that."

That's great for the bottom, but the pressure to the top of the top of the block foundation.

 

[steveray]

Anything is possible..You could ledger off the inside of the foundation but PT floor system might be required depending on how close to grade you are getting...Talk to a contractor and or local building department...Your footing should be 48" in MA...

 

[BobbyK10002]

Anything is possible..You could ledger off the inside of the foundation but PT floor system might be required depending on how close to grade you are getting...Talk to a contractor and or local building department...Your footing should be 48" in MA...

Yes, interesting so maybe not all the way down but even if I can cut the height in half would be good.
Thank you!

 

[ADAguy]

interesting web you are weaving.

 

[Capo]

I wonder if there might be a simpler solution that might meet your requirements but with less work? Is there enough room to get rid of the stairs and put in a very gentle sloped ramp? Possibly install some hand rails as well?