Vaulted Roof Insulation

Insulating an unvented cathedral ceiling.

Vaulted roof insulation.

Remember that a two inch breathing space between the insulation and the roof sheathing must be included to allow for ventilation. Below is 1x decking and 2x4 rafters. To keep fiberglass batts from blocking airflow rafter baffles should be. It provides an open airy look and feel to the room and they are often in demand among home buyers.

Existing is a fourteen year old roof with 2 of closed cell roofing foam with an acrylic elastomeric coating. Bernice from midland ontario wants to know how to get more insulation into her vaulted or cathedral ceiling the common problem with structures like this that we call compact roofs is that there is not usually enough space for a lot of insulation and a lot of ventilation. Foam insulation is an excellent although expensive solution. When renovating an older home whose roof rafters are only 2x6 really 5 1 2 x 1 5 in dimension the available space for insulation and ventilation is limited therefore limiting the options for a combination of good under roof ventilation and high insulation r values in the cathedral ceiling.

A cathedral ceiling is a sloping and pointed ceiling which is usually high and open. Cathedral ceilings built using 2 x 12 roof rafters allow enough space for the fiberglass batt insulation and a 1 5 gap for ventilation. In a vaulted ceiling however the only fresh air route lies between the insulation and the underside of the roof deck. Inexplicably some well built vaulted ceilings complete with vents and fiberglass insulation have moisture problems.

In fact when the only space you have is that left by a 2x8 or even a 2x10 you really can t do a perfect job of both. If space allows the easiest is to install firm insulation batts over the rafters. The drywall becomes stained the insulation becomes damp and the roof wood can even begin to rot. This type of roof assembly is designed so the air can flow up the soffit vent through an insulation baffle pass through the 1 5 gap between the insulation and roof sheathing then exit through a ridge vent.

There are a few different options for installing insulation in a vaulted ceiling. Install vaulted ceiling insulation with batts. But it s not a diy project. Flat roof cathedral ceiling we re going to give it a try.

Cathedral ceilings are a feature in many homes that add to value to the house because the high ceiling tends to make rooms look larger. Cathedral ceilings were once popular due to their grandiose height and appearance but these days many people avoid it because it is difficult to get proper cathedral ceiling insulation installed.