Home>Discussions>TV>Ask This Old House>Attic Fan Install and Roof Safety
4 posts / 0 new
Last post
Attic Fan Install and Roof Safety

On "Ask This Old House" today, I really enjoyed learning about solar attic fans and the installation process. I would like to install one of these in my home. The instructions and demo were great regarding the actual install. I am confident I can do this now. I further understand the importance of roof safety and for the temporary "ledge" and strap. What was not illustrated enough however, for me and I believe may be for others, was how the both the temporary safety ledge and strap(s) were fastened to the roof and how any holes made by those nails, screws, and/or clamps for these safety features were fixed and or sealed at the completion of the project. I learned a long time ago from my Dad, any time you go on a roof you impose a certain amount of stress and damage to the shingles and may invite paths for water damage. Could you help me here regarding this very important part of the install and un-install?

Re: Attic Fan Install and Roof Safety


I assume you have a standard asphalt shingle roof, if not, please specify.

Could you provide more info as to the height of your roof---is this a one-story house, or higher.

Do you have or have access to an adequate aluminum ladder that will reach high enough. Do you have any harness safety equipment---do you have 100 feet of 3/4" nylon rope you can use.

Do you have any pieces of 2 X 4, 2 X 6, or 2 X 10 lumber---do you have any steel roof brackets (see sites below).

All of these items are available at HD/Lowe's or a roofing supply dealer.

Can you post any photos of the roof area you will be working on.

Are there any stout trees, tree branches, or similar secure fastening points on the opposite side of the house that you can secure the rope to.

Do you have rubber-sole gym shoes or footwear that you can use to avoid damage to the roof.

All of us, no matter how many years of experience, have some trepidation about climbing up on a roof--this is part of our survival instinct---any fall from a roof will cause serious injury---and there are all kinds of roofs out there---some are single-story and a mere 10' off the ground with an almost flat or low-pitch roof to boot---these are clearly the safest to work on.

Others are 20 or 30 or more feet off the ground with a steep pitch---these are clearly more dangerous to work on.

The roof should be bone dry without any moisture---there should be little or no wind--otherwise, choose another day.

Keep the ladder (especially a metal ladder) FAR AWAY from any electric power lines.

I always work on a roof with a 3/4" nylon rope tied around my waist, and the other end tied to a stout tree on the opposite side of the house--some people drill a hole thru the foundation & install a large steel eye-bolt & use THAT as a secure point.

It takes time to get to feeling comfortable working on a roof--working at even a slight height---you may want to spend the first part of the day simply climbing up & down the ladder to see how comfortable you are working at the needed height--have someone to help hold the ladder & provide support.

If you don't feel comfortable---go down & get some help or call a contractor.

Once you feel comfortable, from the ladder, start nailing the roof brackets onto the roof with the lumber, as in the photos, to establish a firm, safe platform for you to work on.

The sites below will provide more info.

Also Google "roof brackets" and "roof safety" for more info.

The public library has a number of valuable books on diy roofing in the home improvement section (643.7 stack numbering) that have many other diagrams & photos on how to build your own roof brackets, foot scaffolding, etc.

The "family handyman" site (below) has excellent advice on buying low cost roof brackets which can be attached to a piece of lumber & nailed to the underside of the shingles at various points (see the diagrams).

Once the project is completed & the brackets are removed from the roof, the holes will be mostly covered by the curled up shingle that will cover it.

A small dab of roofing cement (usually black) is applied to any visible nail holes to prevent water leaks.

The "family handyman" site below also demonstrates a SAFETY HARNESS and how it is used, if you intend to do a lot of roofing work.

Please post back with info requested.


Re: Attic Fan Install and Roof Safety

JacktheShack, Thanks for the very quick reply. Your information and weblinks filled in the gaps from what I didn't see on the "Ask This Old House" segment. Re: your questions, I have a new-construction one-story hip roof with asphalt shingles with no sizable trees. I do have a long aluminum ladder. While I have been on this roof once before, and many others in the past, I have just passed the 50 mark. My nimbleness and steadiness are still very good, however I believe it would be wise to add a little more "insurance" with some roof brackets and 2X6 planks when I decide to go up and install the roof vent. Thanks to your information and links, I saw how the brackets install and uninstall. Regarding the safety harness, the diagrams showed screwing in a bracket at the top of the roof on top of the shingles, however I did not see what to do upon unscrewing the harness bracket from the roof line. I would think you would either have replace those cap shingles or use the roofing cement in the exposed holes. Any further thoughts there?

Re: Attic Fan Install and Roof Safety


Yes, you are right---the roof anchor bracket will leave a few screw holes that must be filled with a dab of the roofing cement to prevent leaks.

It would be rare that any cap shingles would have to be replaced--the size of the holes left by the lag bolts is far too small to be seen from the ground.

Make sure you pre-drill the holes for the anchor bracket & sink the lag bolts into the RAFTERS, and not just the roof's sheathing.

If you bang on the roof with a hammer, you should be able to tell from the sound difference the location of the rafters---if not, you can drill a small hole from inside the attic on either side of one of the rafters.

The roof anchor bracket can also be used to secure a length of 3/4" nylon rope to provide you with a line you can hold onto or tie around your waist if you decide not to invest $300 in a safety harness.

The roofing cement comes in 1 gallon cans, but also in a caulking tube, which fits into a caulking gun, which is probably all you'll need to do the job.

Sponsored Stories

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.