Insulate Old House Floors Without Subfloor

If you want to insulate a floor assembly by leaving the joist bays empty and installing rigid foam on the underside of the joists here are a few things to keep in mind.

Insulate old house floors without subfloor.

4b slab floors built directly on the ground. In many cases these floors are casually insulated with fiberglass batts and covered with osb or plywood. 4c as an alternative to floor insulation foundation walls of unvented crawl spaces. Make sure rain drains away from the house on all sides.

It has concrete floors not covered with carpet or anything other flooring it s 22 degrees outside and the hardwood floors upstairs are pretty cool. There are two types of crawl spaces ventilated and unventilated and each requires its own form of insulation. Original floors represent a precious link with the past their wonderful undulations. Your yard should have a 5 slope all around the house.

Under normal conditions a subfloor can last as long as the house itself. In the quest to make our homes warmer and more efficient floor insulation is often overlooked. Also insulate 4a any portion of the floor in a room that is cantilevered beyond the exterior wall below. Without insulation heat and cool air are easily lost through the floor.

If the batts aren t thick enough to fill the joist bays they may fall away from the subfloor and rest on the osb below. To enclose the space in a thermal envelope. But keep an eye out for damage in case you need to replace a subfloor sooner. The goal however is the same.

Insulation can actually make the problem worse by keeping the subfloor cool. Floors above cold spaces such as vented crawl spaces and unheated garages. Although research is needed there are several possible approaches to reduce condensation on the subflooring. A pier and beam home built on top of sturdy supports typically has an open crawl space between the floor of the house and the earth.

Such floors can be found in homes with post foundations in rooms over garages and in cantilevered bays. Unfortunately in old homes this is a common place for heat to escape so it s worth thinking about how insulation can make them more thermally efficient hold heat for longer and protect your home from damp. According to the 2012 irc the minimum r value for floor assemblies is r 13 in zones 1 and 2 r 19 in zones 3 and 4 r 30 in zones 5 and 6 and r 38 in zones 7 and 9. An uninsulated floor allows heat to escape making the house less energy efficient.