Insulation Over Existing Siding

This goes for fiber cement hardwood and masonite siding.

Insulation over existing siding. I ve always wondered if this compromised the r value of the wall assembly. Existing wood siding must be in good shape with no rot or mold and fastened tightly to the wall. Installing vinyl siding over wood siding wood must be sound. By installing insulation on the outside of the framing it causes the location of the dew point to move to the outside of the wall assembly.

Keller sons llc roofing siding windows. Continuous insulation under new siding has become a popular way to improve energy efficiency on an existing home because it addresses a problem known as thermal bridging. Wrap the house with a moisture barrier usually some type of polystyrene wrap and install desired siding by nailing through the foam board into the house framing. This reduces the likelihood of condensation within the wall cavity.

If the wood siding is beveled or lapped you. In other cases it must come off. Never never never let a contractor remove your old siding and install a tyvek material with insulation over the top. Generally the best idea is to remove any existing siding from your exterior walls before installing the vinyl siding.

If you do decide to cover your lap siding in vinyl you ll need to first layer the existing lap siding with highly durable foam insulation and a moisture prevention barrier. In most cases you can put new siding directly on top of old siding without having to remove the old siding first and in addition it will in fact add an addition layer of insulation thereby helping lower your energy bill. It also eliminates the problem of mold forming when insulation is attached directly to the substrate. Vinyl siding must be installed against a flat surface.

The exterior insulation also helps keep the siding all vinyl siding leaks further away from the exterior sheathing. Going over the existing siding adds to the r value by creating an air space between the insulation and old siding. Foam board is however often added in order to help level out the wall when it has certain problems with it. Removing existing siding and installing osb has several benefits such as having brand new substrate on the home and the ability to inspect the wall cavity and all framing insulation and structural integrity of the home before replacing siding.