DIY Home Improvement, Remodeling & Repair Forum

DIY Home Improvement, Remodeling & Repair Forum (
-   Framing and Foundation (
-   -   Need to raise my house... (

Freshmeat 01-03-2007 11:58 AM

Need to raise my house...
I have a (roughly) 950gla house that was built in the 40s. I don't think it's ever been raised back to original height or even professionally leveled. I was out there last weekend and gave it a minor lift on the front since it was significantly sagging and just picking up the front 2-3" to level it, I already have sheetrock finish breaking apart at the joints and whatnot. I'm okay with that- I intend to go through and redo all of it anyway. My problem is this:

It sits roughly 10" off the ground. I'm 6'4" and 245lbs- there's no way I can fit under there to do my plumbing. I've been planning this whole time to have it professionally raised and re-leveled to 34" off the ground (30" piers and 4" thick 24"x24" pads), but that's going to cost $3,500. I was digging up an ant hill that had just begun to reach the siding of the house when I realized the existing piers are buried close to (if not more than) 10" into the ground.

So... if I already have 10" of clearance... and lift the existing piers out of the ground getting another 10" of clearance... and then add the 4" thick pads... I'd have 24" of clearance. I work on cars a lot so I'm accustomed to having less space.

However, would there be any benefit to going with the 34" of lift instead of the 24" of lift? I've read that air circulation under the house is a good thing (still not entirely sure why) but I imagine it can also be a bad thing. Can I please get some advice? I'd like to reuse the existing piers both to save on costs and to keep some of the novelty of the 40s-era build, but if it would be better to go with the 34" I can always just wait a little longer to have the job done.

Any useful advice or further questioning would be appreciated. Thanks!

mudmixer 01-03-2007 01:30 PM

Just a stupid question, but what is a "950gla house"?

Raising a house is usually not a DIY house unless you have experience.

Freshmeat 01-03-2007 01:42 PM

950 gross living area. 950 square feet. GLA is what we used when I worked in the appraisal department for a bank. Habits die hard, yes?

The raise and level will be done by professionals. It's just that a very large portion of the cost is the purchase of all new piers, so if I can reuse the existing piers it will help keep the spending down. The rest I can do myself and despite that I can re-level a house as a maintenance procedure, I don't have the equipment to raise a house two feet in the air to do what needs to be done here, so I'll pay the guys who do this for a living.

glennjanie 01-04-2007 01:34 PM

The existing piers have held the house for 60 years, they certainly can hold it for several more years. I can't picture raising the 10" piers with the house, I would think the house will be raised off the piers and then add to the top of the piers. A clearance of 24" from the ground to the bottom of the joists would be a tremendous help. The air space with proper ventilation will discourage termites and those ants you spoke of. They love damp, dark locations so we ventilate and cover the ground with polyethelyne lapped up on the foundation walls 12" and glued with plastic roof cement.
You can get foundation vents with a metal door on them that can be closed from the outside for cold weather. Each square foot of gla needs 1 square inch of ventilation. In your case 960 sq. in. of ventilation with 124 sq. in. per ventilator, I would use 10 vents equally spaced around the house.

Freshmeat 01-04-2007 03:41 PM

What's all this about ventilation? I was planning to just run a lattice type of trim for skirting... most of the houses in the area don't have anything... can you give me links to something like what you're talking about?

mudmixer 01-04-2007 04:23 PM

Need to raise my house...
I looked at hundreds of homes for the government in your area and in N.O and around/north of Gulfport, MS after Katrina/Rita.

When you have only 10" of ventilation possible, you may have problems. Everything I saw torn out and exposed with that small amount of ventilation and insulation had big time mold. In your climate, it is easy for mold to grow IF you have fiberglass insulation. It does not absorb moisture, but it will hold it.

If you are open underneath with no fiberglass you are probably OK, especially with the old growth wood. Lattice is not bad, but continuous walls, even with plastic and vents can be touchy.

Anything with new growth wood and fiberglass insulation needs as much room for ventilation as possible (and maybe some luck).

I learned one thing during the damage investigation - get rid of wood and fiberglass, especially if you have a hurricane and expect to repair/rebuild.


Freshmeat 01-04-2007 04:35 PM

It's a low area, but the house didn't flood during the hurricanes. There is no insulation on the under side of the house, but I do plan to add some once it's raised and leveled and I'm finished with all the plumbing.

mudmixer- are you saying the lattice should do the job? Should I just leave it open instead?

mudmixer 01-04-2007 06:59 PM

Need to raise my house...

Originally Posted by Freshmeat (Post 7186)
It's a low area, but the house didn't flood during the hurricanes. There is no insulation on the under side of the house, but I do plan to add some once it's raised and leveled and I'm finished with all the plumbing.

mudmixer- are you saying the lattice should do the job? Should I just leave it open instead?

Leaving it open will give you better ventilation than with lattice.

I wasn't refering to flooded homes that had mold. It was just that they did not have enough ventilation in a hot humid climate and had fiberglass to hold moisture and dust.

You have probably been OK because no fiberglass and no new wood (heavier, denser).

Freshmeat 01-04-2007 08:28 PM

I think I'll keep it open, then... and you're saying the roughly two feet of clearance should provide adequate ventilation, yes?

glennjanie 01-05-2007 12:09 PM

Sorry, my rattling along about ventilation was considering a full concrete block foundation. Yes, the 24" will provide adequate ventilation and I vote for the lattice to keep animals out.

All times are GMT -6. The time now is 11:05 PM.