Up Up And Away! ...Scuttle Hatches........Part 3: Insulation as Air Filter
This is something that I see quite regularly. Most people forget that the modern attic is not a storage area of the home. It is a structural service area and is a cold zone. It is outside the thermal envelope of the home. For all intents and purposes it IS outside the home (It's just rain sheltered.)
So what does this mean to home owners. Unfortunately, from the evidence I've seen, to a great many, it doesn't mean a thing.
Why do I say that? What evidence an I seeing?
Well, consider what's shown in the photo above. Yes, it's an open attic hatchway with the ladder positioned and prepared for the inspection.
Already, I haven't even entered the attic yet, but I can see evidence of a chronic problem.
I can see the hatch which is well made of a solid board with rigid insulation glued on it. This is a good detail because it means that when the hatch cover is in the closed position, the hatch area itself is sure to be insulated.
Now look at the other insulation. The fiberglass. The colour. (Originally it was a bright yellow.) Doesn't it remind you of a furnace or car air filter? That's because it is working just like one.
That means there is a constant air flow up arround the hatch to the out side. That's air that you've paid for. No you didn't buy the air but you paid to heat it or cool and filter it.
So that represents money leaving, 'Up up and away'.
If that were happening at a window or door you'd soon be fixing that! So just like all the other openings to the outside it must have effective weatherstriping and latches to keep it closed.
Now please consider this:
If a fire or other source of smoke and/or gas originates in this room, most of the time, it is going to go right out the attic hatch. It will not set off the smoke detector untill much later, maybe only when it is too late.