Video answer · Seal Tech Insulation
Should You Remove Old Insulation Before Spray Foam?
It depends on the condition of what is there and the process being used.
The short answer
It depends on the condition of what is there and the process being used. Insulation that has rodent contamination, moisture or roof-leak damage, or has broken down usually comes out. Spray foam also needs to bond directly to framing and sheathing, so anything in the way gets removed first.
What the crew says in the video
- It depends on the process being used.
- The crew asks: do you have rodents? Degradation? A leaky roof in the past?
- Once those factors are known, they choose the best solution for each individual home.
When old insulation usually comes out
- Rodent nests, droppings, or odor
- Water staining or past roof leaks
- Mold or a musty smell
- Insulation that is compressed, crumbling, or settled to a fraction of its depth
- Areas where spray foam needs to bond directly to the framing, such as rim joists and rooflines
When it can stay
In an open attic floor where the existing insulation is clean, dry, and in reasonable shape, it is often fine to air seal the bypasses and add new insulation on top to reach the target depth. Removing good material just adds cost.
How Seal Tech decides
We inspect before quoting: checking for pests, moisture, past leaks, and the depth and condition of what is there. The estimate says clearly whether removal is included and why.
Not sure if your insulation needs to come out?
We will inspect it and tell you straight.