Insulating the Siding

There are occasions where you can open up a wall and actually blow in fresh insulation with a tool in instances where there was no insulation before or where the existing insulation has been removed. It’s generally not considered a good idea to open up a wall from the outside when there is already insulation present as all the experts agree that this more than likely won’t do much. As well, walls that already contain fire stops, wiring, and vents are not usually good candidates for this type of insulation.

Usually, a siding strip is removed and a new hole will need to be bored to fill the vacant part of the wall cavity. After this is done, the nozzle that sprays the foam can be inserted and the insulation can be blown in. The best way to accomplish this is to insert the nozzle into the holes at the lowest levels and then fill until the insulation reaches the higher points. If you need to see if a cavity has no obstructions, drop a plumb line down into the cavity from a hole high in the wall. The length of the chalk line should be a good indicator of where the obstructions are.

The actual technique that the technician uses the blow the insulation depends greatly on the contractor and the equipment that he or she uses. It makes sense that most of these contractors fill the lowest holes first so that the lowest parts of the cavity fill first as well. Generally they move up row after row starting from the bottom.  Many of these contractors also prefer to use a nozzle that swivels since they can use it to go around obstructions in the wall that might otherwise hinder them.

There should be a few features on the machine itself to prevent the cavity from overfilling and one of these is a pop off value. In selecting the contractor that you want to use, you will need to be willing to do a little legwork as well. Remember that references are invaluable and you should ask for and get them from any prospective contactor that you might be interviewing. It’s also a good idea to ask to see any of their professional affiliations and credentials in the way of licenses or certifications.  It’s important to keep in mind that any decent contractor will have nothing to hide and will be more than willing to show you all this information and may have it readily available in their office, online, or in a brochure.

After the job is done and all the cavities are filled, it’s necessary to plug all the holes with cork or a tapered wood that is usually available from the insulation dealer. After these are installed, a piece of plastic vapor barrier generally goes over the plug.   

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