pier & beam foundations - tell me more

[masraum]

Many of you have probably seen one of my other threads. We are in the process of buying an old home (1920) in the country in central Texas. It's pier and beam and in pretty good shape according to the inspectors.

They did note a few things.

There's some grading issues under the house. To me it looks like water from rain has run under the house and caused some erosion.






The north and west sides of the house have solid metal sheets covering the crawlspace with one spot on the west side large enough to get through. Apparently, you need ventilation all around to allow air to circulate to keep things dry. (except when there's a hard freeze, then you want to block the air to keep things from freezing, according to a website for a foundation company that I looked at) The east and south sides have lattice.






The crawlspace should be covered with something, but not wood, at least, not in contact with the ground.

It's also, apparently not a bad idea to cover the ground under the house with a vapor barrier.

I found a website that said during periods of drought, you may want to water under the house.

I also think that most of the time, some sort of screen or mesh is used to keep small animals out from under the house.

There was one pier (out of ~80) that looks a little crooked. The floors and inside of the home look pretty good. There are some cracks in walls, but nothing big.

The bottom of the house appears to have been hit with a thin layer of spray foam.

So, thoughts on what to run around the outside of the crawlspace that looks good and is functional?

Once we get the ground under the house filled in, thoughts on a vapor barrier?

What about something around the perimeter of the house that might help control water running under the house? Is that a good idea, and if so, what?

[A930Rocket]

It’s been 20 years since we were allowed to build pier and beam foundations, with footers connecting all piers. Structurally, I think they’re ok, unless your in a wind or seismic zone.

I’d definitely look at the drainage around the house, as water should never flow under the house. The dirt under the house should be higher than the exterior and the exterior should slope 6” in 10’ away from the house. 6” from the bottom of the siding/wood,etc. to grade.

You could build what we call hog board between the exterior piers (a 2x4 wood frame with 1x4 or 1x6 horizontal boards) and back it up with stainless steel mesh to keep out the critters.

[masraum]

Originally Posted by A930Rocket

It’s been 20 years since we were allowed to build pier and beam foundations, with footers connecting all piers. Structurally, I think they’re ok, unless your in a wind or seismic zone.

I’d definitely look at the drainage around the house, as water should never flow under the house. The dirt under the house should be higher than the exterior and the exterior should slope 6” in 10’ away from the house. 6” from the bottom of the siding/wood,etc. to grade.

You could build what we call hog board between the exterior piers (a 2x4 wood frame with 1x4 or 1x6 horizontal boards) and back it up with stainless steel mesh to keep out the critters.

Thanks. You explained it better than it was explained in the inspection report. The idea is that the house should be sitting on a small 6" tall mound that extends 10' all around the house. The 6"-10' thing was explained in the inspection report, but it makes more sense the way you explained it.

Definitely no seismic activity here, and I don't think any super crazy wind either in the grand scheme of things. I thought it was bad to have wood down at the ground and running up to the house because that gave termites a way to get to the house.

[look 171]

What's that in the second photo, upper right hand corner. It there a big gap between post and house? Yep, see what's cause of water running into the house. Nip that in the butt. Those posts look so much better then most old house I see around here. they have all been shaken and loosen up too many times over the past 100 years. We are required to strap them to prevent movements out here.

[A930Rocket]

In an enclosed foundation, I recall you wanted about 60-70% of the crawl space covered in plastic. I always covered ours 100% and we had enough closable foundation vents for air circulation and within 12” of the ground for water to get out.

What wood is in contact with the ground?

I’m on my phone and didn’t read the part about wood in contact with soil, but there is treated wood that can.

Except a handrail post in contact, I can’t think of anything that would or should be in contact.

All beams should be supported by the pier. In this picture, it looks like the beam is partially supported and plastic is being used as a barrier between the pier and beam. Used to be you couldn’t have non-treated wood with 18” of the ground and no contact with concrete/masonry. A barrier and/or treated wood was used to prevent contact.

[cabmandone]

All kinds of exterior skirting options available. You could frame down with treated lumber and attach a stone veneer or you could go with some different vinyl options. Whatever you do, make sure you allow for adequate ventilation.

What ties the structure to the piers or to the ground?

[masraum]

Originally Posted by A930Rocket

What wood is in contact with the ground?

I’m on my phone and didn’t read the part about wood in contact with soil, but there is treated wood that can.

Except a handrail post in contact, I can’t think of anything that would or should be in contact.

I was thinking about the "hog board" that you described. It sounds like that would be in contact with the ground or very close to it.

Originally Posted by A930Rocket

You could build what we call hog board between the exterior piers (a 2x4 wood frame with 1x4 or 1x6 horizontal boards) and back it up with stainless steel mesh to keep out the critters.

[GH85Carrera]

My old bachelor pad house was built in the early 1950 and was pier and beam. It was the first house I owned, and I learned a lot about the "joys" of home ownership. Not one bit of plumbing was standard to parts on the market anymore. Lead drainage pipes, worked fine, but couplings are impossible to find.

The one thing I was just ignorant about was the house has to breath in the summer, so uncover the plates covering the access holes. In the winter, make sure they are covered up tight or the pipes freeze and the house needs more heat. My first winter, sure enough the pipes froze. I called a friend that was knowledgeable about it, and we were under the house with very little space, heating the copper pipes with a torch. Finally the water started moving and not one water leak. I got real lucky.

The real joy was getting to my kitchen area. I had to dig a trench under the HIVAC system to have access to that part of the house.

At one point a racoon decided to take up residence under there. Noting like the aroma of coon crap in the morning. I had to trap it, and then make 100% no critters had access. Then go pick up the crap under the house. Golly that was fun.

I guess in Houston freezes are pretty rare, so not a major issue for you.

[masraum]

Originally Posted by GH85Carrera

My old bachelor pad house was built in the early 1950 and was pier and beam. It was the first house I owned, and I learned a lot about the "joys" of home ownership. Not one bit of plumbing was standard to parts on the market anymore. Lead drainage pipes, worked fine, but couplings are impossible to find.

The one thing I was just ignorant about was the house has to breath in the summer, so uncover the plates covering the access holes. In the winter, make sure they are covered up tight or the pipes freeze and the house needs more heat. My first winter, sure enough the pipes froze. I called a friend that was knowledgeable about it, and we were under the house with very little space, heating the copper pipes with a torch. Finally the water started moving and not one water leak. I got real lucky.

The real joy was getting to my kitchen area. I had to dig a trench under the HIVAC system to have access to that part of the house.

At one point a racoon decided to take up residence under there. Noting like the aroma of coon crap in the morning. I had to trap it, and then make 100% no critters had access. Then go pick up the crap under the house. Golly that was fun.

I guess in Houston freezes are pretty rare, so not a major issue for you.

Lots of good info, thanks. Yes, not a lot of freezing, but it does happen. A lot of times we'll have weather in the 50s-70s and then we'll have 3 days of weather that can dip into the 20s and then back into the 50s. So it's probably something that would be Nov - Feb due to the nature of how our cold fronts hit.

Yeah, under the home right now looks pretty spotless (granted, I haven't climbed under it) I'm not looking forward to having to crawl under there, or getting animal life living under the home. Fortunately, it also looks like it's pretty roomy.

[sammyg2]

I'm thinking you board up the entire perimeter of the crawl space except for one little hole, and then shoot in about a gazillion cans of that expanding foam stull from home despot.

On second thought, scratch that. I'm no help at all.

[porsche930dude]

you have no rain gutters thats probably where most of your erosion is coming from

[David]

I've never owned one but we lived in one in Austin during college. Seemed pretty simple to maintain to me. It was really nice when you needed to run speaker wires across the living room, just drill a hole on either end and run the wires under the house

My mom's house in East Texas is pier and beam. She had an issue recently with a soft spot in a room and called out a foundation guy. $1500 later and it was fixed.

[masraum]

Originally Posted by sammyg2

I'm thinking you board up the entire perimeter of the crawl space except for one little hole, and then shoot in about a gazillion cans of that expanding foam stull from home despot.

On second thought, scratch that. I'm no help at all.

No, that's perfect, insulation, extreme structural support, plus it'll lift the house and solve the problem of the land grading!

[masraum]

Originally Posted by David

My mom's house in East Texas is pier and beam. She had an issue recently with a soft spot in a room and called out a foundation guy. $1500 later and it was fixed.

Which beats the hell out of the slab-on-grade. Before we sold our home in Friendswood, we had the foundation fixed. Wow. Not only is it a huge job (I wouldn't want to tunnel under a house), but the process is crazy if you're in the house. They turn the entire house into a pile driver. rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr-WHAM as the house slams down. It feels and sounds like like a bus just ran into the house. Crazy sheisse!

[masraum]

Originally Posted by porsche930dude

you have no rain gutters thats probably where most of your erosion is coming from

I think the inspector mentioned gutters.

[David]

Is this a vacation home or are you moving out of Houston?

[GH85Carrera]

If it does get to the 20s, either close off the opening to the bottom of the house, or at least wrap insulation around the pipes. Frozen pipes are bad!

I had an "energy audit" and they suggested I put in floor insulation. I never did since I had carpet and that helped a lot.

My old house had a HIVAC and the furnace must have been designed for a house twice as big. It would blow 130 degree air from the furthest vent in the back bedroom. I had one guest get cold and she turned the thermostat up 5 degrees. Within 5 minutes I had to open the front and back door to cool the house down as we were sweating. It was insane. It did not have to run but for a few minutes to warm the house up a few degrees on the coldest of days.

[masraum]

Originally Posted by David

Is this a vacation home or are you moving out of Houston?

For the next several years, at least, it'll be a weekend place. My wife watches the grandkids M-F. They are 1.5 and 4.5. I suspect she'll be watching them for another 4-5 years (until they are both in school).

[masraum]

Originally Posted by GH85Carrera

If it does get to the 20s, either close off the opening to the bottom of the house, or at least wrap insulation around the pipes. Frozen pipes are bad!

I had an "energy audit" and they suggested I put in floor insulation. I never did since I had carpet and that helped a lot.

My old house had a HIVAC and the furnace must have been designed for a house twice as big. It would blow 130 degree air from the furthest vent in the back bedroom. I had one guest get cold and she turned the thermostat up 5 degrees. Within 5 minutes I had to open the front and back door to cool the house down as we were sweating. It was insane. It did not have to run but for a few minutes to warm the house up a few degrees on the coldest of days.

The bottom of the house has a thin layer of spray foam insulation which is nice. The inspectors also recommended insulating the pipes under the house, plus the well head, plus the stuff in the pump house.

People are clueless. Usually a change of 1-2* is plenty to make you comfy. So often people will crank an old fashioned analog thermostat 10-20 degrees. I think most folks think a colder thermostat blows colder air or something like that.

This house is 1530sqft, and has a 3.5 ton unit which I think is .5 ton larger than the unit on our old 2000sqft home.

[GH85Carrera]

My parents had a lake cabin. It only had a fireplace for heat so it got super cold in there in the winter. They just poured some antifreeze in the toilet, turned off the water at the ground, and all appliances when they left in the winter time.