Best Type of Roof Rafter or Baffle

[beagle150]

Hi!

I want to install baffles in the attic to prevent existing fiberglass insulation that is on the floor of the attic from blocking the soffits.

My questions:

1) The contractor wants to install durovent baffles. What type of baffles work are best? (northern winters)

2) Will the contractor be able to tell if the soffits are really open when he begins the job? For example, when the job is done, I should be able to see daylight from each of the soffits. However does this mean the soffit is open - just because I can see daylight?

3) Also it is better to install baffles all the way across or only where there is a soffit vent?

- MK

[kurt]

Hard to say without asking more questions, but......

1) Durovent can work. Just about anything semi rigid can work if it's installed satisfactory. You just want to block the insulation from being distributed into the soffits, and free air space from the soffit up into the attic.

2) Maybe. Probably.

3) Depends on the framing and configuration of the soffit, but probably better to baffle all the way across, which most contractors never do, but it might not mean anything at all.

Lots of variables in existing housing that can skew things around; hard to know for sure without seeing it. Pictures are always good.

[Mike Lamb]

What kind of soffit vents do you have? Remove the soffit vent grill from the outside and clear out any insulation after you insulate. Then you know they are clear and you will actually know that there is a real soffit vent. Looking for daylight from the attic may be impossible or at best tricky.

[beagle150]

What kind of soffit vents do you have? Remove the soffit vent grill from the outside and clear out any insulation after you insulate. Then you know they are clear and you will actually know that there is a real soffit vent. Looking for daylight from the attic may be impossible or at best tricky.

Mike,

It "looks like" five soffit vents across the front and five across the back of the house.

Frankly I am not 100% sure that the soffits are open. I assume so as I can see daylight from a few of the soffits from inside the attic. The attic is atop a two-story (1950-ish) colonial and is dry with older insulation (which, due to other projects I will not updating as yet).

I have to hire someone to do this work. I have existing insulation and want to have someone pull the insulation clear of the soffits and install baffles.

Should the contractor have already pulled the soffit grill off (outside) and checked for insulation?

- MK

[Tom Raymond]

beagle,

The easiest way to accomplish what you want is to remove the plywood soffit, push the insulation back as needed from the outside, install the baffles in every rafter bay, then install vented aluminum or vinyl soffit. This of course will also require installing aluminum or vinyl fascias, which in turn will require removing and reinstalling (or replacing) your gutters. It will cost more, but you get something for your investment.

Why wouldn't you have an insulation contractor take care of the baffles as part of an insulation upgrade? If you can see daylight and the attic is dry then the existing vent scheme is working. Modifying it without any particular benefit doesn't make sense (or cents for that matter).

Tom

[beagle150]

beagle,

Why wouldn't you have an insulation contractor take care of the baffles as part of an insulation upgrade? If you can see daylight and the attic is dry then the existing vent scheme is working. Modifying it without any particular benefit doesn't make sense (or cents for that matter).

Tom,

The attic is dry. There is a small section of the eave where we get some larger than usual icicles in winter. My concern was that the area needed to have more ventilation due to the icicles.

The whole attic is insulated but under-insulated (probably done in the 50's or 60's). I can see daylight but not from all the soffit vents (not a continuous soffit). Though the attic is DRY.

Maybe it isn't an issue?

I am testing for radon this January, a second test. And I want to be able to compare it to the test taken this past summer. So I do not want to add insulation yet. I thought getting the baffles in might be somewhat helpful to the roof and prevent those large icicles.

Then it dawned on me to wonder if I would actually know, once the baffles were installed, if the soffits were clear.

I didn't know you could get to them from the outside. We have siding on our home and the placement of the soffits vents isn't really known for sure.

In fact it may be that we have adequate ventilation - maybe we can't see daylight from because the soffit vents are not quite aligned with the vented piece of siding that is over it.

All contractors that have come in to discuss the issue suggest baffles and tell me I ought to have them installed (of course, along with insulation). Most want to sell me foam insulation and I am not interested in that. I want batts as this will be easier to work with, in the future, should I need to get up there and check on things.

Maybe I ought to simply put it off until next year. What I believe I understand is that this condition should be known by the contractor and/or insulation contractor and that I may have to pay someone to check to see what is going on first (open it up from the outside or inside?)

We got up in the attic yesterday, but it was impossible to tell what was going on even when we got out to the end of the rafter. The insulation lays on the floor of the attic out to the "end" (that is what I can see). Day light peers out in some areas, but I can't see the actual soffit vents.

Further advice or thoughts are welcome.

- MK

[Tom Raymond]

The attic is dry. There is a small section of the eave where we get some larger than usual icicles in winter. My concern was that the area needed to have more ventilation due to the icicles.

More insulation will do more to prevent ice build up than increasing ventilation will.

I am testing for radon this January, a second test. And I want to be able to compare it to the test taken this past summer. So I do not want to add insulation yet. I thought getting the baffles in might be somewhat helpful to the roof and prevent those large icicles.

Modifying the vent scheme could impact the radon test results. I would finish the radon testing before changing anything.

I didn't know you could get to them from the outside. We have siding on our home and the placement of the soffits vents isn't really known for sure.

I assumed from the description of the house that it still had the original plywood soffits, and now it sounds as if they are under the vinyl. Generally around here the plywood soffit would be removed, or at least have a 2-3" wide slot cut into it to gain ventilation before covering it with vinyl.

All contractors that have come in to discuss the issue suggest baffles and tell me I ought to have them installed (of course, along with insulation).

Installing the baffles is the labor intensive part of the job. The insulation and the labor to put it down are cheap, around here I would be very surprised if the insulation was more than a few hundred more than just doing the baffles.

Maybe I ought to simply put it off until next year.

That's a personal choice but; there are tax incentives available for energy efficient improvements, and you would be more comfortable and begin recouping investment dollars this heating season if you did it now. And you might fix that ice problem that started this topic.

We got up in the attic yesterday, but it was impossible to tell what was going on even when we got out to the end of the rafter. The insulation lays on the floor of the attic out to the "end" (that is what I can see). Day light peers out in some areas, but I can't see the actual soffit vents.

If you got that far you have a good understanding of what you are asking your contractor to do. Pay him a few hundred more to insulate the attic while he is up there and it may be worth his effort.

Tom

[hausdok]

Hi,

It sounds like ventilation is fine but you're getting too much heat loss into the attic. Before you add a whole lot of new insulation, go through the attic and trace every pipe and wire back to where it enters the attic and seal around them with some Daptex expanding foam. Put some foam rubber gaskets behind all of the switches and receptacle covers and make sure there's a decent gasket on the attic hatch and that every exhaust fan that passes through there isn't leaking into the attic anywhere. Add your new insulation using the existing vent scheme and I think you'll be fine.

ONE TEAM - ONE FIGHT!!!

Mike

[beagle150]

Tom, Mike,

Thank you for your thoughts.

Tom your point about the radon test was a good one. We will wait until after the January radon test before changing the venting / insulation system.

In the meantime, I am going to try to hire someone to actually go up and see and/or check from below as to what the situation is.

As a homeowner, I find it would be easy to hire someone to do x or y with regard to these issues and never really know whether some of the work was actually dnoe (or had to be done).

So I might as well find out how many soffit vents we have, if they are open.

One last question. Apparently there are three types of baffles: cardboard, foam and plastic. I'm opting for the plastic because I've heard foam can crack. I've heard that I would have to check the foam baffles yearly (doubt I would do that . . . does any homeowner do this???).

What types of baffles are best? Do you really need to check the baffles after they are installed on a yearly basis?

- MK

[Brandon Whitmore]

cardboard, foam and plastic

You could make your own out of plywood. Cardboard ones are typical around here, and work well when properly installed.