Questions About Spray Foam Insulation

The material itself does not wear out. It is a rigid plastic bonded to the framing, so it will not slump, settle or compress the way loose materials do across decades. Closed cell gives up a little resistance in its first couple of years as the blowing agent stabilises, which is why the sensible planning figure is around R-6.5 an inch rather than the R-7 that sometimes gets quoted. After that it is stable. What ends an installation early is almost never age. It is a proportion that was wrong or a surface that was too cold, which is a first day fault that only becomes visible later.

It will make the house airtight, which is the objective, but a tight house needs ventilation by design rather than by accident. Depending on leaks to ventilate means the most fresh air arrives on the coldest windiest night and the least arrives when you would actually like some. Provincial code work is heading toward blower door verified airtightness for that exact reason. Where we tighten a house significantly we will tell you what it means for ventilation and whether heat recovery belongs in the plan. That conversation happens at quote stage.

Almost never, and the reason is worth knowing. Foam has to bond to something solid. Applied over batts or loose fill it grips the insulation instead of the framing, which leaves you with neither a seal nor an assembly to depend on. It also buries whatever condition the old material was in, damp included. The old material comes out first. The exception is a cavity the foam is not being applied into at all.

Cured foam is inert and stays exactly where it was applied. What needs managing is the curing period, while the chemistry finishes, when the space wants ventilating and emptying. The manufacturer's re-entry window reaches you in writing before the work. Fire performance is a separate matter, and it is why occupied rooms require a thermal barrier over the foam, half inch gypsum board being the usual answer. Foam left showing in a finished room is not a compliant installation no matter how good the foam is.

For the walkthrough and the handover, ideally. During the application and the re-entry window, no, and in fact nobody can be in the space at all. Most houses are a single day. We arrange access, protect what is staying, ventilate mechanically, and walk the finished work with you afterwards alongside the job log.

The floor band, in most houses. It is a narrow strip of framing sitting on top of the foundation, thin, weather facing, usually with next to nothing in front of it, and responsible for a share of the total air leakage far out of proportion to its size. Two or three inches of closed cell around the perimeter is short work at a modest price, and it is the one people report noticing first, because the floor above stops being cold. Where a budget covers exactly one item this year, that is normally where we point it.