Different foundation technique question
Hello,
I am not an experienced poster, and am kinda shy bout this compooter stuff, but love spending time on this forum.
Any ways, today I met with a client and his architect to discuss an addition to existing house project. The architect was trying to convince us of a design that he loves for the foundation/wall. His premise was that his method is more cost effetive, easier to insulate/ and easier to finish frame than what most people out here are doing.
Basically, He digs a trench for the footer, fills it halfway with 3/4″ gravel, sets stakes to establish grade for a sill plate, builds stud wall using PT 2×8 at 12″ o.c., sets wall on top of grade stakes, and fills rest of footer with gravel (packing gravel under wall).
Then wall is sheeted with 3/4″ all weather wood, and plastic sheet used for waterproofing.
That is his reccomendation for a basement wall system or even a first floor with a crawl space. (which is what we are doing). He cites the advantages of not having to utilize a concrete crew, only having to do minimal excavation, (no room needed for forming system), better insulation with a 2×8 stud wall, and not having to frame a basement to a concrete wall(Doesn’t apply to us). I know this architect has been doing this for awhile with some well regarded builders in the area, and he says that the 2003 IRC shows it. (Which we use here, I’m gonna check the book when I get to my office on Monday).
I called some one I knew that had worked on one of his projects, and got their side of the story. Basically, she said that it worked well, only thing they weren’t ready for was the weight of soaking wet PT 2x8s during framing and wall standing. They had to use a crane to stand the walls.
The way I see it, studs at 12″ o.c. don’t allow for effective insulation, and will be a pain for sparkys and plumbers.
As the GC, I’ll build whatever design the owner eventually goes for, But I was really just wondering if this was as good a system as he archy says?
Any opinions (Besides me being longwinded)
Thanks
Replies
me .... i'd go for it...just bid it accordingly ( a little learning curve )
it's like going to school on someone else's nickle..
the owner & HIS architect like it..... approach it with an open mind and enthusiasm
it could be the beginning of a long relationship with this architect
I tried using treated wood for a small job I did on my own house but after a few years I ripped it out and put in a block foundation wall. The treated plywood that I removed was sopping wet but I mighjt have done it all wrong. I don't know. I seem to remember back in the 80's they were tooting something like a 30 year guarantee which to my mind is nothing.
A couple of years ago I was looking at a house to buy and though it looked pretty good from the outside the price seemed too low. The real estate agent said they were having trouble selling the house because it had a wood foundation. Knowing that I didn't even look at it.
roger
done right ( with correct drainage ) and the required PT treatment level ( 0.6)
it should be fine
i'm not a big fan, but if this is what the owner & architect want, then i'd give it to themMike Smith Rhode Island : Design / Build / Repair / Restore
Its not something your architect came up with. Treated wood foundations were all the rage in the 1980s. The government here in Canada pushed them heavily, and did a lot of research on them.
If you decide to build that way, I'd suggest you take a look at how they did them and compare it with what your architect has speced. I'd also ask him why you don't see them any more. If he is using an unconventional foundation system he should be aware of its history.
Be a little cautious about thinking you are just along for the ride as GC following the architect's design. If problems occur later you may find it harder than you think to shovel the responsibility his way.
Good luck.
A friend of mine built with a similar system. I was very skeptical especially when he backfilled with the excavated clay. I thought for sure the weight of the soil would deflect the wall but, 5 years later, there has been no problem. I am still not convinced that it will last for the long term but he's from central Canada and said that this method is tried and true. I say - we'll see.
My neice and her husband did this about 12 years ago. Put in a full basement with treated wood foundation. They did have a problem in one area where something collapsed and had to be rebuilt, but the repair actually was (he had a backhoe) relatively easy. Much easier than if he had ceement walls. Which of course, he wouldn't have had the damage...
"{sets wall on top of grade stakes, and fills rest of footer with gravel (packing gravel under wall)"
Wood foundations aren't new and there's plenty of information available to prove they will work. However....I'm not buying into that "packing gravel under the wall" thing. If they'll amend their technique to leveling the gravel, then setting the wall on the level gravel, then I'll agree that it's a good system.
I've done one. I created a 4' high wood framed wall for a mobile home on a crawl space. The 4' walls were HEAVY. We had to use two wall jacks to raise them and they weren't that long.
Bob's next test date: 12/10/07
He's right that it is in the Code as an option. I don't know that his conclusion about the cost comparison really justifies using the system. It has been around a while, but doesn't seem to be really popular. Why not? Could it be the annoyances of building heavy walls full of lumber that's soaked with chemicals? Could it be the unknown of how long the stuff will last, or the fear of finding an intrinsic weakness after the fact? I would ask him for some of his experiences and ask how much he's researched the long term performance. I know from a resale standpoint, a lot of people won't touch them. That's the main reason that I'm not using the system on one that I'm involved with now.
It's interesting, but as lots of people have said - just because you can, doesn't mean you should.
Don K.
EJG Homes Renovations - New construction - Rentals
Hi all,
Not sure how to reply to everyone at once.
For the record, the arch referred to the Canadians use of this system in his presentation. The owner is doing the addition to create resale value. He wants to "Go Green" for marketing reasons. The arch is noted in the area for his successes in sustainable building. I have been involved in sustainable building before I went on my own, and I would like to eventually be known as one of the better sustainable builders in town.
Having said that, I doubt the claims of "Greenness" by building a foundation with poisonous wood. I am aware that what we are using today for wood treatment is supposedly less toxic. But toxic is toxic, and after a day of working with these new PT materials, I can tell it still isn't good for you. I also have doubts about the long term effectiveness of products that have not been real world tested.
I am still eager to try this, cause that's how ya learn. After talking to my framer, it turns out that he has done this before, and likes it. Mostly cause money in a project that the concrete guy would get, goes to him instead, and also cause he can take responsibility for a square foundation. (it's nice having a framer willing to take accountability). This is a small addition, and I'll be able to monitor the building for as long as I care to. That makes it a good candidate for this type of venture. Note: our area is fairly arid, so I believe it is well suited to this approach.
For now, when I get drawings later this week, I'll be able to price it. Until then, I am going to follow the conversation about wood foundations in the green building discussion folder.
Thanks everyone for your help.