Ask The Home Inspector !
Under Construction


CRAWLSPACES
WHAT IS A CRAWLSPACE?

A crawlspace is an enclosed space between the underside of a floor assembly and the ground with a vertical clearance of less than 5'-11", but more than 12"; an 18" minimum clearance is recommended in termite areas.

By insulating and heating the enclosed space, the floor temperature of the room above will be more comfortable. proper ventilation or air circulation and a sound ground cover will reduce dampness, improve air quality, and ensure against dryrot.

RECOMMENDED DETAILS TO IMPROVE THE CRAWLSPACES.

Insulation
  • Perimeter walls - preferred material is rigid board type - use at least R-12.
  • Floor cavities - (recommended only if crawlspace is unheated) - use fibreglass batts (R-25).
  • Air ducts - use fibreglass pipe wrapping (R-5).
  • 6 mil vapour barrier should be installed to the warm side of the floors and walls and should also wrap air ducts.

Heating (options)
  • Modify existing air duct system to install heat supply outlet in crawlspace.
  • Modify existing hot water system to install a radiator in crawlspace.
  • Install an independently controlled electric baseboard heater in crawlspace.

Access
  • At least one access opening (20" x 28") should be provided (could use an existing basement window)

Ventilation
  • Ventilation should be provided to adjacent basement spaces via an existing window opening.
  • Vents should be uniformly distributed on opposite wall sides (open in summer and closed in winter).

Ground Cover
  • Install overlapping sheets of 10 mil polyethylene plastic weighed down with fine granular material.
  • Install 2" of concrete.