Roof Question

[Palomino]

Hello all.

I have a circa 1986 Wick Rollohome 16x66. It has a regular shingled and peaked roof like a regular home would have. Being that the roof is a little over 20 years old I think it's time to have it redone.

Now I have heard that its not wise to do a roof over on a mobile home because the roof might not support the weight of two layers of shingles. So, I was thinking of having a metal roof installed possibly over the existing shingles. I believe that a metal roof is much lighter then singles. Is it possible to do this?

Any other advice would be greatly appreciated

Mike Krivsky
Athelstane, WI

[Archie]

Rather than installing metal over the shingles it wouldn't be that much harder to just remove the old stuff first, a couple of square end shovels will pop it right up. You will have an added cost of replacing the felt paper but you will also have the ability to inspect the plywood for any damage.

[Jim from Canada]

Most contractors worth their salt will not add a second layer of shingles. Always strip off the old ones.

[Dean2]

Yes it's good to remove and replace but over the years I've done tear-off of multiple layers here in NE IA on lots of different structures.

The trusses generally transfer the weight to the exterior walls (and to the occasional weight-bearing interior wall) wich then transfer it to the floor and in a mobile home to the piers,blocking or whatever is underneath. In most cases I would think adding reasonable weight would hinge on how well it is supported underneath and the walls themselves..

If it is framed around windows/doors and such properly and well supported under then I would think since it was manufactured with a heavier peaked roof then it can support a little more.. If it is a steeper roof and snow load will slide off that's a plus too,,being in WS I think You should deffinately consider the possible snow load.

Ultimately if all is well above then the support underneath is where every pound ends-up having the most effect and that's where I would inspect 1st to decide about adding weight. Then the exterior walls as there are surely clear spans without interior load bearing walls.

Look at it all (maybe get an inspector)and think about how that weight's going to push down on the outside edges and floor till it gets to the ground.

I used to work on Wick modulars(DW finish in field) back in the 80s and they seemed to be decently built,,,in Mazomanie if I remember right.

Dean

[Jim from Canada]

It has nothing to do with weight, it is all about doing the job right. Tear off the old ones so you can determine if you are just covering up problems. Also, any visual discrepancies will show through the next layer of shingles in a short period of time. Put a layer of ice/water sheild under the shingles. The recomendation is the bottom 3' with the rest done in felt "tar paper". I like to see ice/water shield eave to peak.

Jim

[Greg]

Dean, You have to remember that in mobile home construction the floor joists do support ALL of the weight of the roof & walls. If you add too much weight the joists will bow down on the sides unless there has been perimiter blocking added. Greg

[Dean2]

Greg,,I thought I adressed that when I said,,"Look at it all (maybe get an inspector)and think about how that weight's going to push down on the outside edges and floor till it gets to the ground. ".. Granted it is'nt an exacy statement but then We ai'nt writin a book,,Mark already did that! Just kiddin man,,I think We're basically on the same page.

Jim,,I think You're right for the most part but it sounded like Mike wanted to know if He could save time/money and just overlay it with steel.. I think He could but should check to make sure that it's properly supported,,that's all. I do get Yer idea tho,,I've had to tear off multiple layers that went back 50 years or more and it's a pain..The roof sheeting might be looked at from underneath if Mike can get access from and end and crawl inside with a light. What He wants to do is'nt perfect but might be do-able.

I gotta remember to attache an "I'm just a drywaller" disclaimer to more of My posts...

Dean

[JD]

Looking at all of the replies to the original post, I would say they are all accurate. Dean did cover his statements by calling for an inspector and checking the build of the home. I also liked Dean's point that the metal roof may be more snow friendly. It sounds logical to me but I don't have any snow experience here in Fresno, CA.

I would really like to echo the suggestions to remove the existing shingles. Of all the mobile home shingle roofs I have dealt with, there has only been a couple that did not need at least one sheet of sheathing replaced. I have also seen many roofs where more than half of the sheathing needed replacing. So finding some deck damage is almost expected when I replace a roof. Fasteners going into water damaged sheathing are the same as skipped entirely. You would also know that you are not exceeding weight limits for your home.

JMO
JD

[Greg]

Dean, you did say that, however there are people that read the posts here and leave parts of the advice out (like the inspector part). I just wanted to make sure that the worst case result was spelled out. Greg

[mrfixit64857]

To throw my two cents in, I have replaced my shingled roof with a metal one. I LOVE it. My advice, though, is that even if you GO with a metal roof, to remove the shingles anyway. If you DON'T, every wind will be a noisy one, with the mineral coating of the shingles scratching the metal. I also laid down 30 LB felt under mine as well. so as to aid in quieting the metal. works like a charm!

[Yanita]

Hi,

A couple more cents added here...In Mark's manual is an easy to follow DIY instructions for installing a metal roofover. Look in the books/parts link above.

Yanita

[Palomino]

Thanks all for the responses. Lots to think about.