Putting Insulation In Cavity Walls

If your home s got cavity walls fitting cavity wall insulation can be one of the most cost effective ways to improve your home s energy efficiency and reduce your energy bills.

Putting insulation in cavity walls.

Insulation in house exterior walls is one of the primary defenses against heat and energy loss. What do you do if you have an un insulated wall in your home. Cabling can be difficult to run at the best of times but what happens when you drill a hole in a plaster wall with the intention of running a cable from the roof cavity down to this hole and find it filled with insulation. While rated differently these two types of insulation are close enough in thickness that they can both fit into modern two by four wall systems.

There are various grades of insulating batting for different locations in the house so you ll need a different insulation for interior exterior attic or basement walls. Unfortunately however builders didn t insulate the walls of most homes built before the 1980s. Most homes built in the past 100 years are built with two layers of wall leaving a small space a cavity between them. Put the batt in place and use a scissors to snip around the box.

Tuck the snipped out plug of insulation behind the box. In most wall applications you will use r 13 or r 15 kraft faced fiberglass insulation rolls for these two by four stud walls. Running a cable down an insulated cavity wall. The r value of the batt measures the thermal resistance so the higher the r value the more effectively.

In a perfect world you would be able to unscrew invisible bolts remove drywall panels install insulation and reinstall the panels our less than perfect world of permanently attached wallboard means time consuming hacking away of gypsum individually removing drywall screws or nails installing r 13 or greater fiberglass roll insulation and re installing the drywall. That creates gaps and air convection routes around the box. In early days of using cavity wall construction 1920 s in modern domestic buildings the cavity was thought to be enough of a barrier for damp penetration. So if your house was built before insulating walls became standard you can potentially save a great deal of energy by insulating.

It s a common issue and it can be fixed using our slow rise foam it green formula. Cavity wall construction ready for cavity insulation the earliest use of cavity wall was way back in greek and roman times but it wasn t until much later that things have got interesting.