My plans were to have an asphalt roof for my 25x25. I am now reconsidering given the exhorbitant prices for OSB/plywood that a metal roof may be less expensive. I would just put purlins over my trusses and apply the metal roof without OSB/Plywood. Haven't priced it out yet, so has anyone else considered this?
Metal or Asphalt roof
- Thread starter Theruse
- Start date
rburke65
Well-known member
Assuming you mean the corrugated stuff that one sees on barns etc? That would work, and plus is that you could put the clear polycarbonate ones in for skylight lighting if needed.
All the ones I see in New England however do seem to rust after 10 years or so?
If you paint them white with the exterior paint then you’ll keep heat down as well as keep them from rusting longer.
White is the only color that for a house roof is considered energy efficient. FYI.
All the ones I see in New England however do seem to rust after 10 years or so?
If you paint them white with the exterior paint then you’ll keep heat down as well as keep them from rusting longer.
White is the only color that for a house roof is considered energy efficient. FYI.
readhead
Well-known member
If your building was designed to be sheeted you can not just replace the sheeting with purlins because you will be eliminating the roof diaphragm. Some kind of diagonal bracing will need to be installed. And, no the metal sheeting does not provide the shear.
Buckgnarly
Well-known member
If you just use purlins and go wide, you will get WICKED wind noise. My neighbor made that mistake on his vacation house.
bradpac
Well-known member
I would go metal over shingles, just based on performance, but I've been in the industry for 17 years so my opinion might be a little biased. I know metal has gone up almost double since the beginning of the year though, and still rising, not sure how shingle costs have done.
If your building structure is designed for a solid roof deck, you can still put metal on it, but the cost savings for the sheathing will obviously not be there. Of course, then you can use a 1" or 1.5" architectural type panel, which will be a little cheaper than a structural panel.
If you go for metal over purlins, you will need to make sure it's a structural double lock or snap lock usually 2" or 1.75" tall ribs. I put the 1.75" tall snap lock style on my new 30x30 garage with 4' on center purlins.
If your building structure is designed for a solid roof deck, you can still put metal on it, but the cost savings for the sheathing will obviously not be there. Of course, then you can use a 1" or 1.5" architectural type panel, which will be a little cheaper than a structural panel.
If you go for metal over purlins, you will need to make sure it's a structural double lock or snap lock usually 2" or 1.75" tall ribs. I put the 1.75" tall snap lock style on my new 30x30 garage with 4' on center purlins.
volleyball
Well-known member
So you are looking at a standing seam roof. Don't worry about color as a metal painted roof is more reflective than a rolled or shingled roof. And panels with baked on finish do not rust in decades.
I have a 12 x 14 shed with a shed roof. I roofed it with the 3' wide panels. To cut down on noise, I used foam panels in place of the sheathing and it has worked out great,
A lot of barns have no sheathing under the metal roof. I just don't know if I would be happy working in one during a storm
I have a 12 x 14 shed with a shed roof. I roofed it with the 3' wide panels. To cut down on noise, I used foam panels in place of the sheathing and it has worked out great,
A lot of barns have no sheathing under the metal roof. I just don't know if I would be happy working in one during a storm
racecougar
Well-known member
Provided you install a ceiling and insulate the attic, storm/wind noise is nil.
nadogail
Well-known member
Have you considered repurposed 55 gallon steel oil drums?
If can get enough of them, have enough space and equipment to cut off the ends and roll them out flat; they give you a fairly large panel that can be used like a giant shingle.
In my area they are often available for free on Craig’s List.
If can get enough of them, have enough space and equipment to cut off the ends and roll them out flat; they give you a fairly large panel that can be used like a giant shingle.
In my area they are often available for free on Craig’s List.
Sounds like an interesting idea for a shed roof.
matt_i
Well-known member
Agreed you need to take a look at the truss instructions (assuming its built like that) for bracing before making a decision.
Downside of open-underside metal (no insulation, no decking) is a rainstorm can easily start inside if conditions are correct.
If I wanted to save money on a 25' square I'd put up the shingles myself. Once you get a synthetic/woven underlayment down the building will be so watertight you couldn't tell the difference, its just a matter of UV protection (lap over the peak andthen slice open the ridge vent slot in the underlayment right before you do that step). Then you can take several weeks to hand apply the shingles. Hand nailing gets excellent results in proper placement and drive-depth and you can put 5 nails per shingle which increases the tear-out resistance markedly. It does not have do be done all in 1 day.
readhead
Well-known member
On a 12:12 metal would be a lot more work than shingles.
racecougar
Well-known member
Agreed. That will not be a fun install.
dcg9381
Well-known member
Insulation is easily accomplished with spray on foam and the performance is excellent also.
Having lived in my shop for about 1.5 years while building a residence and the roof of that building being metal over purlins, with 3-5" of foam insulation, I can tell you that when it rains hard, you cannot have a conversation in that structure. This would be mitigated (perhaps substantially) by having traditional attic space.... I've just never seen it done on residential this way - dunno why.
Here, we are subject to substantial hail. Asphalt roofs simply do not last 20 years. Metal certainly is the way to go (assuming you don't mind the hail dings) for overall maintenance (and insurance) costs. The up-charge for metal roof (standing seam?) over roof decking - it blew the roof costs up about 300% though.
TractorJeff
Well-known member
I would do metal roof over shingles due to the fact that it will outlast shingles and the replacement cost of the 2nd shingle job.
Our house has a metal roof, so I did a metal roof on my garage and on my shop. In the insulated portions, it is not noisy.
My brothers who all live in NYS have been replacing their roofs as needed with metal supplied by the local Amish community.
Heck, they will even install it for you!
Our house has a metal roof, so I did a metal roof on my garage and on my shop. In the insulated portions, it is not noisy.
My brothers who all live in NYS have been replacing their roofs as needed with metal supplied by the local Amish community.
Heck, they will even install it for you!
Mikeske
Well-known member
I will do nothing but metal and get several quotes for the installation. I have a manufactured home and got 15 years out of the 3 tab shingles and I thought I got lucky with no leaks but after the fifth year I was up on that damn roof ever 6 months inspecting and repairing damage. 15 years ago I had a complete tear off, had several sheets of plywood replaced (or should say had plywood replace the cheap OSB) had additional insulation installed with batten strips and had a standing seam metal roof. The best money I ever spent as yes I still go on the roof once every year to check and kill any mud wasp that get near the vents but I think I put in one small strip of chalk and that is it.
When I decided I was going to metal I had decided I never want to be constantly repairing the roof as I was getting older and I rather stand on the ground then the roof and I look at the metal roof on my home and say I went to a 50-75 year roof from a 15 year roof. So if the price is two to three times the cost of those blow off specials I still way ahead
When I decided I was going to metal I had decided I never want to be constantly repairing the roof as I was getting older and I rather stand on the ground then the roof and I look at the metal roof on my home and say I went to a 50-75 year roof from a 15 year roof. So if the price is two to three times the cost of those blow off specials I still way ahead
joshmodelskidoo
Well-known member
Use some sort of under layment between the steel and perlins. That gets rid of any moisture from temperature difference inside vs outside
readhead
Well-known member
All that does is trap the condensation between the metal and the underlayment causing rust on the sheets. It won’t rain inside but the roof will rust through. Insulation evens out the temperature difference and stops the warm moist air from reaching the cold sheets.
bpjr
Well-known member
Putting metal on battens fastened to trusses works but for lowest cost it will have to be a screw down deck instead of standing seam. If you look at the metal roof mfg specs most (if not all) say underlayment is needed to repel any water that gets past seams and fasteners. Without decking or an underlayment, butyl tape is commonly used for sealing this way but strips of self sealing "peel n stick" underlayment would work way better.
I DIY a 24x16 shed screw down over existing shingles with battens 10+ yrs ago and no problems.
Also have 5 yrs on 120 squares of screw downs on two other buildings and zero problems. These have ply decks with peel n stick underlayment.
I DIY a 24x16 shed screw down over existing shingles with battens 10+ yrs ago and no problems.
Also have 5 yrs on 120 squares of screw downs on two other buildings and zero problems. These have ply decks with peel n stick underlayment.
readhead
Well-known member
Another option is to use SSR commercial panels which do not require a substrate. A bit more expensive and requires some special tools.