Recommendation for new boiler

[Robert Pauly]

OK I'm confused. If the aluminum is vented, but there is a solid wood soffit behind it then what is it venting? If the aluminum was installed properly the installer would have made sure there are vent openings in the original wood soffit. Most of the homes in the area do have vent openings in the orig wood soffits. If you don't the best way to accomplish this is to drill a series of holes from the outside in. A good 3 or 4" hole saw will accomplish this. Then you will need to purchase aluminum covers for the holes you drilled. I would make sure you have the covers (round vented grills) before drilling.

Thanks to all, you're really helping me on this.

As to the question above, I doubt that the aluminum vents are venting anything - maybe they are - maybe the aluminum installer did insure that there were vent openings in the original wood soffits - but I'm not so sure.  And even if he did provide enough venting for an unfinished attic, is there enough for a finished attic?  Maraire - your idea sounds good - with the saw I could drill through the aluminum and wood soffits - but every rafter width apart?  That's a million holes!  In that case, I'd take Naz's suggestion of refinishing the original wood soffits (no - I wouldn't really do this!), but I'd probably avoid finishing the attic and build a shed for the kids in the yard instead.  I could probably get bunkbeds in there.

Or would the air from a few vent holes travel along the soffit and eventually make its way between each rafter?

I think your right about cutting away a portion of the floorboards, Bons.

Sorry for hijacking this thread.

[watcher]

If we're going to finish our attic, we'll need to insulate between the roof rafters, and I'm told that there's a proper way to do it.  First, a ridge vent will have to be installed on my roof. 

The soffit end of the venting seems to have been covered well. The ridge vent can be accomplished within the existing roofline using an interior "trough" and vents situated above the trough. Venting the length of the ridge as a retrofit project is very complicated. Your roof style/design determines where venting is needed. As long as all the rafter spaces are vented to a vent chase, simple roof vents will give adequate air movement.

There's undoubtedly a formula to determine the size and air flow needs. I don't know it and doubt that builders apply it, except generally.
The science is fairly forgiving until you get into air-tight envelopes which isn't a big issue for our leaky boxes.