Harrowsmith – September 2019

Harrowsmith Fall 2019 | 193

Coldwintertimefloors(and
cold feet) are one of the biggest
drawbacks of older homes, and
the strategy for warming them
up depends on the situation
you’ve got.
Are your floors cold because
they exist over an unheated
crawl space? Don’t bother trying

toheatthespace.Crawlspaces

are difficult to insulate and seal

well, so they can suck up huge

amounts of heat while offering

only minimal benefit for your feet.

Better to insulate the floor from

the underside, but don’t use batt

insulation stuffed between the

joists. This is a common approach

Strategy No. 3: Warm the floors

HOME & DESIGN: OLD-HOUSE ENERGY UPGRADES

requires extension of interior door

and window jambs.

3. Boost wall cavity R-values
   This approach is minimally
   disruptive and can be highly
   effective, but only if your wall
   cavities are truly hollow. The best
   approach uses slow-rise, two-part
   polyurethane spray foam injected
   into wall cavities. Injection from
   inside is easier and simpler,
   requiring only small patches in
   the drywall to cover injection

holes. Foam can be injected from

the outside, too. Foam gives off

heat as it cures, allowing areas of

foam coverage to be easily seen

with an infrared camera.

Pros: Very significant boost in

wall R-values with no significant

disruption of interior or exterior

wall surfaces.

Cons: Only practical with hollow

wall cavities. Use of infrared

camera needed to verify presence

of foam in all walls.