DIYbanter - View Single Post - Insulate basement + crawl space walls to save energy?

aemeijers

wrote:
Live in 60 year old 1300 Sq Ft single story brick house with full basement,
it has recent 600 Sq Ft addition with about 3' crawl space. Live in Michigan
(zone 5) and winter heating bills are a killer. My basement is very cold and
drafty in winter...in dead of winter temp check showed around 37
degrees...I have hot water heating too by the way. The House came with newer
Anderson windows and two years ago I blew cellulose insulation into all
walls that were not insulated...also added about 6" in attic....so total of
about 12" of cellulose there. Oh and I also did my best to caulk everywhere
possible in basemen last winter, but seemed not to help much.......I have
noticed that the inside walls of basement are like ice cold to the touch
too. would it be worth while to dig down a couple of feet and insulate the
outside of basement and crawl space?? If so how to do it? Any advise
appreciated...

Worth it as in a more comfortable house, yes. If you can tie the
foundation wall temp to ambient below-frostline depth temp, the basement
and house will be a lot more comfortable. It almost becomes a bermed
home if you do it well enough. Worth it on payback period, is a whole
'nother question. Unless you have the strength, willpower, and time for
DIY, it is a lot of manual labor to insulate below frostline on the
outside. And I do mean manual labor- it is almost all hand work, unless
you want to destroy the yard and all plantings. Hand labor=expen$ive.
Most people give up some R-value to save front money, and insulate on
the inside. Often overlooked spot- is the band joist insulated, above
the sill plate but below the first floor decking? Also common to get air
leaks right at the sill plate, if they didn't gasket it correctly before
they laid it out.

Standard caveats apply about not creating leak paths by skinning the
wall, and having a vapor barrier on the cold side of the wall. Unless
your upper walls already happen to stick out unusually far, you will
need a big Z-flashing at the top of the insulation, and it will look
funny. May be able to disguise it with a wide trim board something. They
sell faux-stucco finish hi-density foam panels for the very application
you are thinking about. They go up with construction adhesive, and you
can even get color-matched putty and a texturing roller to hide the joints.

--
aem sends...