Ask Me Help Desk - Crawl Space - broken supports, seal dirt floor, and trash

My house has a 1 room addition with a crawl space. The crawl space is adjacent to a full basement and there is ample ventilation between the two.

I don't need regular access to the space - I need to be able to get into if there is a problem with the room's plumbing or electrical. Or if there is a leak on the side walls, which at this point are sealed off well (from water, not moisture). The crawl space and basement are damp, but there aren't puddles or standing water.

Problems with the crawl space include:

1/2 ton of leftover drywall, household trash, large rocks, and construction debris are strewn across floor.

The floor is dirt.

Several posts are lying on the ground - I assume they used to function as supports.

A few posts are haphazardly set up with pieces of wood jammed in between floor and post.

A huge pile of rubble is stacked up to the ceiling. It's possible that this pile is serving as a support function.

The room above has a significant tilt, which leads me to wonder if the tilt is related to the dysfunctional support system.

Which problem should I deal with first?
The trash
The supports
The dirt floor

I am considering just covering the debris with plastic and letting it stay there. I already removed a 1/2 ton of trash and it is now relatively flat. Some people recommend putting down limestone or sand under and/or over the plastic.

How should I go about fixing the supports?

Thanks,
Michael

Hi Michael

Your first problem to deal with, in my opinion, is the structure supports of room.

How much is tilt and from main house is it toward outside wall?

What is size of room? The number of support beams is relative to size of room. U may be able to jack up room to eliminate tilt. U may have to put in footings for support beams.

What is closing in the crawl space?

Remove as much trash as needed to work in area safely.

Second problem is trash. After supoort work is done, remove ALL debris. The trash is good breeding ground for rats and other vermin.

Last problem is the dirt floor.

Make sure u have enough ventilation. Lay plastic over dirt and cover with either a skim coat of concrete or stone.

Good luck

Chuck

Chuck, thanks for your thoughts.

Quote:

Originally Posted by creahands

How much is tilt and from main house is it toward outside wall?

I estimate the tilt is about 6.5 inches across the diagonal of the room. The tilt is away from the house and to the side. Outside the crawl space there is a wooden beam at the sunk-in corner.

Quote:

Originally Posted by creahands

What is size of room? The number of support beams is relative to size of room. U may be able to jack up room to eliminate tilt. U may have to put in footings for support beams.

The room is 15 X 21.
In the crawlspace there are support beams running along the left side, perpendicular to the shared wall with the house. The beams that fell down are the ones closest to the house and at the highpoint of the tilt. I presume the room sank to the back and to the right, allowing the posts on the left-front to fall to the ground - since they were not bearing weight. The rock rubble pile is at the back middle.

Quote:

Originally Posted by creahands

What is closing in the crawl space?

It has brick walls on all sides. Except the wall that is shared with the house has some sections cut out. One gives access to the space, another makes room for stairs into the basement.

How should I go about adding supports and/or jacking it up?

Hi Michael

Before I go on can u post some pictures?

Is the brick wall cracking because of tilt? Do u have any window or doors in room?

How is room attached to main house?

Have never jacked up a room that much. Most I have done is 2''.

Normally, added on rooms are attached to main house and support beams are on outside wall running parallel to main house.

Chuck

Brick wall is not cracking. There used to be a space between the top of the brick wall and the wood frame, but I have since filled in with spray foam and mortar.

The room has 3 windows. An interior door to the rest of the house, exterior door, and a door that leads into the basement.

Notes on attachments:
1) This is the support at the low point of the room. As far as I can tell, the rest of the exterior support is brick. The gray stuff around the post is mortar. The brick is covered with a layer of mortar.
2) Joint between interior brick wall that separates basement from crawlspace
3) Left side of crawlspace - taken from the vantage point of the basement. Floor board supports running parallel to house. Support beams from floor ceiling are at the backside. The ones nearer are laying on the ground. (There are other interior floor to ceiling beams other than the walls)
4) This a view of the middle of the crawlspace. Just to the right of the previous photo. Notice the big pile of rubble that may be serving a support function.
5) right side of crawlspace. Rubble pile on left is the same as the previous picture. No supports visible. The back of this picture is the low point of the room.

Does this help? What other information or photos can I give you?

Hi Michael

Need some time to study pics.

I assume the 12' side of room is attached to house.Is this correct?

Will have some info for u in morning, my time.

Chuck

Quote:

The room above has a significant tilt, which leads me to wonder if the tilt is related to the dysfunctional support system.
Which problem should I deal with first?
The trash
the supports
the dirt floor

If you want a class A job done here.
OUTSIDE
1. Check all gutters for flow and down spouts far enough from the foundation so water issues are present for sinking.
2. Check grade around that sunken corner so water doesn't sit there

INSIDE
1. Remove rubble, But before that use it to re wall up that one side which appears to be blowing out and possibly allowing heavy rain water to seep into the crawl space. That water movement will cause the sinking you have over time.
2. Check sister joist ,I see scabbed Joist on the side of the old joist, which indicates the old are splitting/cracked and that's where the post are.
3. If some of the old joist are sagging and cracking then that needs addressed so lets hit them all
4. Pick out the center of the crawl space. In both directions this is where the first New center Pier will go. Scrap to virgin ground so you can form and set a 24"x24' area poured with concrete.
5. Form up that center pad with 2x6. so we end up with a 24"x24' square pad out of 2x6 to get our concrete 6" deep. Use 3/8 rebar in the concrete pour.
6. Make two more of these in that same center line ( Long wall perpendicular to joist) at each end of the inside foundation
7. Pour pads let cure.
8. lay 8x8x16 block jambs side by side on the 3 piers.

PIERS HEIGHTS
This is where it gets a bit tricky to catch the joist evenly. String line that center and keep the line down form both end joist bu wall equal distance. Go to the most center joist and measure down 10' this is where the center Pier block height should be. Use that center Pier as a bench mark to level the other 2 piers.
After the piers are laid level to each other you can use tripled up 2x10s to make a beam to set on top of those piers. The 2x10s can be cut so they meet in the center Pier. Set 2x10 beam From there you can build up shims/boards to catch all the floor joist. Before you put the shims in Nows the time to cut sister floor joist and screw them onto the old joist. They also can be cut in the middle where those shorter lengths meet on top of the new center 2x10 beam. This will greatly help installation to work them on to the ends of the old joist.

There are options her that you can use a bottle jacks and jack up the sagging center joist to level out some of the dip. And them add your board shims above the 2x10 to lock it in.

This I'm sure sounds like a bit extreme project but it address ALL the joist and properly sistering the old. It also gives you the option to re bottle jack another year to take more center dip out of the floor.

The extreme here is jack up the one corner but that will only hold if the foundation stops sinking. By all intense and purposes if you have proper drainage away from those walls and patch up the wall(S) so surface ground water doesn't run into the inside things should be fine. Even though the basement doesn't get water or not reallying seeing it in the crawl space doesn't mean some is seeping in form that collapsed corner, which I feel is the culprit here

The finial thing here to do is lay a 6mil plastic on the dirt floor for a moisture barrier. And to spray foam the joist bays for insul

Quote:

Originally Posted by 21boat

If you want a class A job done here.
OUTSIDE
1. Check all gutters for flow and down spouts far enough from the foundation so water issues are present for sinking.
2. Check grade around that sunken corner so water doesn't sit there

INSIDE
1. Remove rubble, But before that use it to re wall up that one side which appears to be blowing out and possibly allowing heavy rain water to seep into the crawl space. That water movement will cause the sinking you have over time.
2. Check sister joist ,I see scabbed Joist on the side of the old joist, which indicates the old are splitting/cracked and thats where the post are.
3. If some of the old joist are sagging and cracking then that needs addressed so lets hit them all
4. Pick out the center of the crawl space. in both directions this is where the first New center Pier will go. Scrap to virgin ground so you can form and set a 24"x24' area poured with concrete.
5. Form up that center pad with 2x6. so we end up with a 24"x24' square pad out of 2x6 to get our concrete 6" deep. Use 3/8 rebar in the concrete pour.
6. Make two more of these in that same center line ( Long wall perpendicular to joist) at each end of the inside foundation
7. Pour pads let cure.
8. lay 8x8x16 block jambs side by side on the 3 piers.

PIERS HEIGHTS
This is where it gets a bit tricky to catch the joist evenly. String line that center and keep the line down form both end joist bu wall equal distance. Go to the most center joist and measure down 10' this is where the center Pier block height should be. Use that center Pier as a bench mark to level the other 2 piers.
After the piers are laid level to each other you can use tripled up 2x10s to make a beam to set on top of those piers. The 2x10s can be cut so they meet in the center Pier. Set 2x10 beam From there you can build up shims/boards to catch all the floor joist. Before you put the shims in Nows the time to cut sister floor joist and screw them onto the old joist. They also can be cut in the middle where those shorter lengths meet on top of the new center 2x10 beam. This will greatly help installation to work them on to the ends of the old joist.

There are options her that you can use a bottle jacks and jack up the sagging center joist to level out some of the dip. and them add your board shims above the 2x10 to lock it in.

This I'm sure sounds like a bit extreme project but it address ALL the joist and properly sistering the old. It also gives you the option to re bottle jack another year to take more center dip out of the floor.

The extreme here is jack up the one corner but that will only hold if the foundation stops sinking. By all intense and purposes if you have proper drainage away from those walls and patch up the wall(S) so surface ground water doesn't run into the inside things should be fine. Even though the basement doesn't get water or not reallying seeing it in the crawl space doesn't mean some is seeping in form that collapsed corner, which I feel is the culprit here

The finial thing here to do is lay a 6mil plastic on the dirt floor for a moisture barrier. And to spray foam the joist bays for insul

Thanks for the rundown. It is a bit intimating, but the step by step makes a lot of sense. There used to be major drainage problems. The yard has a negative slope towards the crawl space and the downspouts used to empty at the edge of the house - although not at the most tilted corner.

Your saying I should take the rubble and pile it ground to ceiling in the tilting corner? Using the rubble as a support? It's possible the big rubble pile is already serving this function, so I gather I shouldn't remove those rocks until new supports are added.

In the pick it looked like the rubble was part of that back side of the foundation wall. If so that coupled with the bad drainage which I highly suspected let water in over time to cause the sinking along the walls weakest point.

Unless someone was trying to get rid of the rubble from digging it out to build the new walls I would suspect it was the wall until it slid down onto the dirt floor.

Either or Tidy it up and get some clear space to work in and clear space to lay poly down.

The first main objective is to stabilize the wall and ensure water doesn't seep/run to stop any more sinking. Then Pier it.

Quote:

Originally Posted by 21boat

In the pick it looked like the rubble was part of that back side of the foundation wall. If so that coupled with the bad drainage which I highly suspected let water in over time to cause the sinking along the walls weakest point.

Unless someone was trying to get rid of the rubble from digging it out to build the new walls I would suspect it was the wall until it slid down onto the dirt floor.

Either or Tidy it up and get some clear space to work in and clear space to lay poly down.

The first main objective is to stabilize the wall and ensure water doesn't seep/run to stop any more sinking. Then Pier it.

The exterior walls are brick and the rubble is cement or something similar. I had figured that it was a cement patio that was dig up to build the addition and left the rubble in the crawl space.

Either way, it makes sense that I need to build new supports. Thanks for the advice!