Concrete piers

Lifted79chevy350 · Tue Oct 12, 2010 12:47 pm

The back of my mobile home is starting so sag a little bit it looks like they just put the concrete blocks on some non treated pallet wood. I have a 20 ton jack and a water level is easy to make. Looks to be 3 blocks stacked. When I go to re level the rear end wouldn't it make more sense to stagger 2 blocks next to each other? Lay 2 down side by side then the next 2 laying cross ways then the next set the other way. Common sense says that this will also spread the surface pressure out am i right and is it better to just leave them stacked the way they were before?

JD · Tue Oct 12, 2010 7:40 pm

Alternating directions makes perfect sense to me. I don't work with blocks so I can't say for sure which way is code, but I would think that code would agree with us. Be sure to use proper hardwood shims and blocks when you raise the home. You can probably use the shims that are already there, but they are available online and at most MH stores.

Lifted79chevy350 · Tue Oct 12, 2010 9:11 pm

Well I would think better stability even if i do it at the end. I did find a site that had abs plastic shims for .30 each. Ill order a few just in case I need to replace them. Forgot to bookmark it. though.

Lifted79chevy350 · Thu Oct 14, 2010 11:12 pm

I snuck a look under my neighbors newer trailer and its just single stacked blocks like mine but it looks like they made there platforms out of treated wood 6 2x4 stacked crossways set on the ground. I dont know if it would help to put some visclean or something down to help with moisture. the ground undeneath the trailer was never very good to begin with. Now can I do this in the winter time i know it kinda dont make sense cause the ground will be frozen but im deathly affraid of spiders (Ever seen a 27yo man scream like a 12yo girl.)

JD · Fri Oct 15, 2010 7:14 pm

Studies have claimed that you are always within 10 ft of a spider.

Oh no! I did-dint say that!

Lifted79chevy350 · Sat Oct 16, 2010 12:03 am

Lol thanks JD (WHILLIES) =). If I don't see them I'm OK. I'm going to get in a bubble like bubble boy. And DeWalt needs to be paying you for that. Thats a perfect for an add. And your dog is a good lookin pup.

Greg · Sat Oct 16, 2010 8:23 am

If you are on your own land, you could dig down (major pain) and use poured concrete & sono tubes. that would put an end to the problem. Greg

Lifted79chevy350 · Sat Oct 16, 2010 10:53 am

No im in a park and the soil is clay so mud when wet and hard as a rock when dry my underside ground is not very good at all im going to have a hard enough time getting the wood out of the dirt thats under the piers now. When i get them out does anyone have any recomendations as far as putting dirt or sand or gravel down under the piers? Otherwise I was thinking about getting some fill dirt down and compacting it with a BFH.

JD · Sat Oct 16, 2010 2:15 pm

I work with the pressure treated pads often. What I have seen in old home set ups is, pads sitting above the dirt line have remained in good condition after 30 years or so. Pads that sunk more than 1 1/2" tend to rot in 10 years or so, due to the dirt holding moisture against the pad almost constantly. You may consider using an ABS plastic pad. These have the same code use clearance as the mobile home pressure treated wood pads but won't rot.

I think the pads are important to concrete block piers in giving the piers a bigger footprint as well as distributing the pressure so the blocks don't crack.

Lifted79chevy350 · Sat Oct 16, 2010 3:44 pm

ok that makes sense. Prolly what happened to mine here. and what if I just put some thick 6 mill plastic then set the treated wood on it then blocks? I know im a cheap bloke. I also saw that you like the metal instead of the blocks. Are they cost affective compared to blocks and wood?

JD · Sat Oct 16, 2010 8:14 pm

I don't know about using the sheet plastic just at the piers. Totally covering the ground with 6mil plastic under the mobile home as a vapor barrier is a good thing, but it still has to stay dry. Water from rain drainage, sprinklers or plumbing leaks still should not stand around the pads. The ABS pads would be good for this reason. But plastic just at the pads might hold water instead of keep it out.

Steel piers probably cost more than the concrete blocks. You need a pad, pier and lock top. mobilehomeadvantage.com shows piers for ~10 to 12 bucks and ABS pads for $7. I didn't see pier tops though. In my area, we need locking pier tops (bolt clamp). You need to check with your local code to be sure they allow metal piers, what type of tops (saddles), if they can be mixed with concrete block piers, all that kind of stuff.