New foundation blocks for crawl space

[Carth]

Hello,

Are solid concrete blocks be the recommended replacement for the bricks in the pictures for my crawl space block foundation?

 

[Jeff Handy]

Post some pics showing a wider, farther back view.

It seems like these old brick piles are supporting beams in your crawl space.

Are they just resting on dirt?

Ideally, you would excavate down a foot or so, tamp the bottom of the hole firmly, and pour a square or round concrete base about a foot or more across, then you can install a steel jack post pillar on that, with an adjustable screw to tighten or raise up as needed.

The top of the post will have a square steel plate that can screw into the bottom of the beam for stability.

If pouring concrete is not possible, you could excavate a square hole a foot deep and about a foot and a half wide, tamp the soil firm, flat, and level, then fill the hole with a stack of heavy one foot square paver blocks with wire mesh inside them.
Backfill firmly around the blocks, make the stack a little higher than the soil level.
Then install the jack posts.
You will need two posts, or another system of support, where you have half lapped beams resting on a brick pile.

You will need to install temporary jack posts on both sides of the old bricks piles, to be able to remove them and install new supports.

This whole process is very dangerous, a beam could easily collapse and cause structural damage, or could crush and kill you down there.

You should hire a pro for this project.

 

[Carth]

Post some pics showing a wider, farther back view.

It seems like these old brick piles are supporting beams in your crawl space.

Are they just resting on dirt?

Ideally, you would excavate down a foot or so, tamp the bottom of the hole firmly, and pour a square or round concrete base about a foot or more across, then you can install a steel jack post pillar on that, with an adjustable screw to tighten or raise up as needed.

The top of the post will have a square steel plate that can screw into the bottom of the beam for stability.

If pouring concrete is not possible, you could excavate a square hole a foot deep and about a foot and a half wide, tamp the soil firm, flat, and level, then fill the hole with a stack of heavy one foot square paver blocks with wire mesh inside them.
Backfill firmly around the blocks, make the stack a little higher than the soil level.
Then install the jack posts.
You will need two posts, or another system of support, where you have half lapped beams resting on a brick pile.

You will need to install temporary jack posts on both sides of the old bricks piles, to be able to remove them and install new supports.

This whole process is very dangerous, a beam could easily collapse and cause structural damage, or could crush and kill you down there.

You should hire a pro for this project.

Wish I could hire a pro for this. We do have someone who is assisting with jacking up the house but I haven’t spoken to him in regards to what we’re replacing the bricks with.

Funds wise I don’t think I’ll be able to buy all of those jacks for a permanent setup.

Would a block setup like they are doing in this video work? https://m.youtube.com/watch?v=ABTxWB7TMKI

If so would you dig out that foot for the concrete then place the cinder blocks on it just as you would for the permanent jack setup?

 

[Jeff Handy]

I think the blocks look good.

In the video, it looks like they are just stacking blocks on the dirt, which is not good.

Even digging out just a few inches, tamped and level, and setting one solid concrete block pad as a base, would be better than just loose blocks on dirt.

You can buy precast pads at home centers.

Your helper for the jacking should be able to advise.

Be careful, you can die down there in about two seconds.

 

[joecaption]

All my company did for about 15 years was work on 100 plus year old houses and repaired things Like I'm seeing in those pictures all the time.
In your case the first thing I would do is treat for Powder Post Beetles, that's what all those ice pick sized holes are.
https://www.domyown.com/how-to-get-rid-of-powderpost-beetles-a-326.html
Next I would figure out how many piers I was going to be replacing to figure out how much concrete, rebar, solid block and steel plates I was going to need.
https://www.calculator.net/concrete...ickunit=inch&slabquantity=1&slabcal=Calculate
Next we would make up 24" X 24" X 6" pressure treated frames to act as forms for the concrete.
Dig out some 6" deep pits for the forms to set in making sure the frame sat level.
(There is no need to remove any of the old forms at this time.
A hoe with the handle cut off, or one of those folding Army shovels works for this.
To get the concrete under there we would use a mixing pan with a strong rope on each end, one for pulling it in, one for pulling it back out.
We would put 4 pieces of 1/2" rebar in the middle of the pore.
To get the blocks under there I had a flat cart that I also attached rope to.
I made the forms 24 x 24 for several reasons, #1, It gave them enough foot print that I knew they would not sink much. #2, It gave me a wide enough area to set a bottle jack if it needed lifting without being in the way of the blocks.
Do not use wood as a shim, use 1/2" steel plates!
Only use solid blocks, there is no need to mortar them in place, I'd never lay just a single row stack of them.
Trying to use one of those preform pads will just crack if you try to use a jack on it.
When using the bottle jack make sure there's a thick steel where the piston touchs the wood or it will just crush the wood.

 

[Carth]

All my company did for about 15 years was work on 100 plus year old houses and repaired things Like I'm seeing in those pictures all the time.
In your case the first thing I would do is treat for Powder Post Beetles, that's what all those ice pick sized holes are.
https://www.domyown.com/how-to-get-rid-of-powderpost-beetles-a-326.html
Next I would figure out how many piers I was going to be replacing to figure out how much concrete, rebar, solid block and steel plates I was going to need.
https://www.calculator.net/concrete...ickunit=inch&slabquantity=1&slabcal=Calculate
Next we would make up 24" X 24" X 6" pressure treated frames to act as forms for the concrete.
Dig out some 6" deep pits for the forms to set in making sure the frame sat level.
(There is no need to remove any of the old forms at this time.
A hoe with the handle cut off, or one of those folding Army shovels works for this.
To get the concrete under there we would use a mixing pan with a strong rope on each end, one for pulling it in, one for pulling it back out.
We would put 4 pieces of 1/2" rebar in the middle of the pore.
To get the blocks under there I had a flat cart that I also attached rope to.
I made the forms 24 x 24 for several reasons, #1, It gave them enough foot print that I knew they would not sink much. #2, It gave me a wide enough area to set a bottle jack if it needed lifting without being in the way of the blocks.
Do not use wood as a shim, use 1/2" steel plates!
Only use solid blocks, there is no need to mortar them in place, I'd never lay just a single row stack of them.
Trying to use one of those preform pads will just crack if you try to use a jack on it.
When using the bottle jack make sure there's a thick steel where the piston touchs the wood or it will just crush the wood.

Thanks for the response Joe.

I was wondering what those black holes are. So going off that picture would you advise replacing that piece of wood?

We were going to replace all of the floor joists but we might have to replace the beams or piers (whichever their called) now that you point out that of the wood beetles.

I just bought the house 2 months ago so we’re working to fix the moisture problem in the crawl space. Having gutters installed soon and then will be encapsulating that crawl space.

Can the boracare or timbor potentially save that wood or does it need to be replaced?

 

[joecaption]

No inspection was does before you bought this place?
No treatment is going to fix damage done already, it will just help future damage.
99% of moisture issues needs to be addressed outside of the foundation not under the house once the damage has been done.
There's just no way anyone can advise you on what needs to be replaced without being on site, anything else is just a well meaning guess.

 

[Carth]

No inspection was does before you bought this place?
No treatment is going to fix damage done already, it will just help future damage.
99% of moisture issues needs to be addressed outside of the foundation not under the house once the damage has been done.
There's just no way anyone can advise you on what needs to be replaced without being on site, anything else is just a well meaning guess.

I did have an inspection. He told me and wrote it up as no foundation issues.

I see now that he either didn’t go in the crawl space or does not know what proper foundation looks like.

 

[joecaption]

Way far to often we all have heard this one before, most often from out of towner's that ask the realtor who they use.
If they failed it they would never get another referral from them.
In my local area when trying to help out past customers that where looking to buy an older house like that had "charm" needs work but had "good bones" that asked me to come inspect it, before I even left the house I'd ask them how much money are you willing to pay out to fix it knowing at least 90% of the time there was going to be hidden major issues.

 

[bud16415]

There is certainly nothing wrong with @joecaption approach. If it were mine and being a home owner of several of these old places with similar issues I would go after it a bit different or at least 30-40 years ago I would have when I would take this on.


First as mentioned above proceed with extreme caution.


Secondly keep in mind this house weighs a gigantic amount and it has settled over a century of time and is not going to be corrected without causing more issues than you fix. The goal should be to stabilize and give yourself peace of mind and not try and take out 100 year old swaybacks in the floors above. If you want to get rid of them you can deal with that from above with the next layer or flooring or if you plan on taking it down to the joists sister on something to make a flat and level base.


I wouldn’t touch any of the supports that are in there now if at all possible and not touch any of them until the new supports are in place.


I would go with pre-made 8x8x16 solid blocks for about 5 bucks a pieceand make my footing a double side by side block and depending on height a second or third layer finishing with a single lined with the beam. Some shimming will then be needed and steel plates would be nice but PT 2x8 or plates cut from PT plywood I feel would carry the weight fine.


Getting these blocks in and out I would rig a sled with pull ropes similar to mentioned above.


If the floors will be removed it would make it all easier working from above thru the joists.