MENU

by • October 31, 2011 • FoundationsComments (7)15738

Pier & Beam vs. Slab Foundations with Mark LaLiberte

  Last week one of my building science Heros was in Austin speaking about High Performance Homes.  If you’ve never seen Mark LaLiberte speak you are really missing out.  I first heard him speak about Building Science in 2002 when I was working in Portland, OR.  The mold scare was just breaking into the national news scene and I was working for a luxury production builder as their Production Manager.  I was building 150 homes a year with 7 Project Managers and 3 Service guys and the mold scare hit us hard.  Our company actually bought back a home from someone who had mold in their walls and several other houses had major re-construction to deal with mold.  We were building houses like we always had, but weren’t really thinking about long term durability or the science behind moisture flows.  One thing I learned from Mark back in 2002 was that 80% of building failures are due to water issues so you’d better become an expert as a builder at controlling water and it’s forms/movements.
  Anyhow, the point of this post is that I talked Mark into visiting one of my job sites on his way to the Airport and I made this quick video as we talked on site about foundations.

  So, now that you’ve seen the video here my pro/con list for Slab & Pier/Beam.
CONCRETE SLAB FOUNDATIONS:
Pro’s
1.  No water issues under your house
2.  No bugs/rodents under your house
3.  No floor framing costs – Option to do stained/polished concrete at your finished floor
4.  No frozen pipe issues

Con’s
1.  Hard to correct plumbing issues & hard to remodel plumbing in the future
2.  Hard to re-level the house if there are movement issues
3.  No insulation at the floor line and concrete is a huge thermal sink
4.  I think concrete floors are hard on your knees & joints

PEIR & BEAM FOUNDATIONS:
1.  Easy to remodel & move plumbing
2.  Easy to add wiring or phone/cable lines under the house
3.  Insulation under the floor is really good.  (Spray foam please)
4.  Wood framing provides some “give” when you walk
5.  Relatively easy to re-level the house if movement occurs

Con’s.
1.  Can have water issues in the crawls space depending on your grades.
2.  Need to be vigilant about keeping bugs & rodents out of your crawlspace
3.  Possibly more expensive flooring costs with framing & hardwoods
4.  Possible pipe freeze issues

Ok, so do we have a clear winner?  No not really.  It really depends on your site conditions to determine what type of foundation is best for your lot.  All things being equal I lean towards pier/beam foundations but that is certainly not a one-foundation-fits-all recommendation.  Talk with your engineer and your builder, see if you can determine how older houses in your area have performed.  -Matt Risinger

Related Posts

  • Hi Matt,

    Enjoyed your posting on the pros and cons of foundations. I have a lot which slopes down about 5′ over the 90 foot length of our proposed new house. The ground is a mix of limestone outcroppings and soil. What foundation would be best, concrete slab or pier and beam? I have concerns about critters getting under the house as we are in a rural area. Thanks for your advice.

  • Matt,

    I always enjoy and learn from your videos! I am remodeling a rent house I own and have the same idea regarding the crawlspace wall. On this home, what type of siding/finish do you plan to put over the steel studs? Any vapor barrier under there? Thanks. Keep ’em coming.

  • @rickmagers: Thanks for the complements! On this house the skirt has a metal stud that is screwed to the wood perimeter beams and then the bottom track is held in place with rebar drove into the ground. That way it has some ability to move without cracking. We did 2 coat stucco on top of those steel studs.
    No vapor barrier in the crawlspace just 4″ of open cell foam sprayed on the underside of the floor.

  • @jwcates3: It sounds to me like your rocky ground might be a good slab candidate especially with the concerns about animals underneath. However, 5′ out of the ground is pretty tall. Talk to your engineer, it sounds like it could go either way. -Matt

  • In Austin a major “pro” of a concrete slab is the thermal mass cooling effect in the summer. This same characteristic can be a “con” in the winter. Although not to be underestimated, it really helps on the electricity bill and comfort levels — whole house temperature is very stable.

  • @ Eddie Moderow: Yes there is a ground cooling effect but overall the slab edge being exposed is a net negative effect for the year. The next big step in efficiency for Austin’s slabs will be perimeter insulation. Beyond that is perimeter AND under slab insulation. Stay tuned for future info on this. I’m working on a design now for future Risinger Homes jobs. Thanks for your comments! Matt

  • Cynthia Thornton

    I’m hoping to build a one room cabin soon and I’m trying to decide. I kind of wonder about the heat issue they talk about with concrete – I have some concrete floor in my present house and every time I put my bare foot on that concrete floor it feels cool or cold depending on whether it’s summer or winter but I have yet to experience any heat from that floor. I live in Arkansas where the summers can be pretty hot and humid and that concrete is always cool to the touch. So I con’t really understand why they say it collects and radiates heat.