Hoping to get some advice on Barn Roof

[chado613]

I have an old barn with metal roof. (See attached pics)

Its a bit rusty and has numerous small leaks likely coming from seams and screw/nail gaskets.

I have had 2 different roofers come in the past to "fix" the leaks however all they did was put more screws into the metal, In hind sight, putting more holes into the roof was probly not the best way to stop leaks.

I have had another contractor come by and he suggested a silicone coating (Gaco Roof gaco.com/product/gacoroof/)

Has anyone had experience with this, I see it used alot on flat roofs and some people say that water cant get underneath it and cause damage.

The stuff is pricey at approx. 400$ cdn for a 5 gallon pail so I any past experiences with this is gre3taly appreciated.

Also the roof is steep enough that I do not feel comfortable going up there myself otherwise I would probly start the tedious process of replacing the nails/screws and sealing the seams myself.

 

[KennyG]

The coating works but it the existing corrosion on your metal is going to be an ongoing problem. It will probably damage the coating from underneath. If your structure is solid, I would recommend having new metal put on. With a good contractor, it's a one time cost and you are good for another 40 or 50 years.

 

[ponytug]

Sorry about your roof issues. Unfortunately, I think it comes with the territory, metal roofs.

Mentally, I think, "that is a metal roof, it should last forever." But metal roofs do need maintenance and repair, and it looks to me like you are there.

One thing to clarify: are the fasteners still solidly holding the roof with crumbled or shrunk gaskets, or have the fasteners lifted enough to allow water under them? In the first case, a sealant would help, in the second, you need to redo the fasteners.

I have old metal roofs on the barn and out buildings. All of the washer gaskets on the fasteners are dying or dead. In most cases, I have removed (pulled/unscrewed) the dead fasteners and replaced them with a new 3" screw. That works great where the original screw/nail went into a beam and it isn't rotted out. I have a few where the fastener went into a slat. I put a larger diameter short screw in, seal it with roof sealant, and put a new screw in on an adjacent, better board. In a few cases, the new screw doesn't seal because the metal is too uneven, and I have put sealant on top of the new fastener.

The absolute worst are some really old nails with a metal seal (lead? Aluminum?) that seem to shed the head of the nail, and then leak. When you glance at them on the roof, they look ok, at least until you wise up and realize it is a headless, leaking nail. Then you have the issue of countersinking the old nail to get the new one in. Second prize goes to some twist shank aluminum nails with a washer that is so hard it feels like polycarbonate. Four out of five times the head comes off rather than the nail coming out, and I usually twist while pulling to get even one out of five.

I don't know about the gaco product, but I use something similar (Henry Tropicool 100% silicone) and it seems to hold up well. One of my older roofs is coated with a coating and it seems to have held up. One thing that I look for is a guarantee that it will work in standing water. Many aren't guaranteed, and will get lifted off the metal by water lying against it. Given that your roof has been painted and has rust, I would double check what surface prep is required for the sealers.

I think that metal roofs are trickier to work, and a lot more dangerous than asphalt. Metal roofs are very slick, and a little dew or dust goes a long way toward greasing your descent off the roof. So, I think you are being smart to delegate the job to professionals.

All the best,

Peter

 

[drssg]

I would also vote for a new roof. By the time you pay for labor, the sealant will be a costly option, and you're still left with patchwork on an old roof.

In the pictures, it looks like a combination of nails and screws have been used over the years, with some on the ridges and some on the low spots. I think placing screws consistently on the ridges works better.

After removing the current roof, they can/should replace any rotted wood from old leaks. It's a significant expense, but hopefully you'll never have to mess with it again.

Good luck.

 

[Deere Dude]

Kinda looks like my 40x60 barn roof. Mine is 6/12 pitch so it is doable as far as walking on it. I did get a harness and lanyard so I don;t get a runaway for near the edges.

I was worried about wind getting uner the edges so I put pole shed caps on the edges.

I pressure washed it then came the tedious task of finding loose nails and screws that were missing roof joists. How the corrugated steel stayed up there I'll never know. I pulled a gallon or more of very skinny small headed nails and many screws with bad washers.

I replaced non-solid nails and screws with oversized pole barn screws on the holes. All the holes missing joists I patched with a certain clear caulk that doesn't shrink, kind of like silicane but a contractor steered me to it but the name escapes me...

Once I couldn't see anymore holes and snugged all the existing screws up and added many screws I washed it down again.

For the maybe 200 sq foot of rust, I painted with Osphro, a rust restoring chemical on the rusted parts. Once that was dry I sprayed Rustoleum Forest Green on the whole roof. That was about 4-5 years ago and all is good yet.

I did find a few nails and screws missing the joists and a few holes I missed, but hardly anywater comes through anymore.

A fairly reasonable fix that still looks good.

 

[ponytug]

@drssg X2 on screw on high points. Always. Fasteners in the valleys is asking for a leak.

I tend to do cost benefit analyses all the time, so I agree that doing the math on replacing the whole roof makes sense.

All the best,

Peter

 

[fried1765]

@drssg X2 on screw on high points. Always. Fasteners in the valleys is asking for a leak.

I tend to do cost benefit analyses all the time, so I agree that doing the math on replacing the whole roof makes sense.

All the best,

Peter

My metal (Morton) barn roof is 37 years old and does not leak.
It is beginning to show very slight rust (salt air).
I assume it will last at least another 10 years,..... but I will likely not.
I have told my sons they should just have it replaced when the time comes.

 

[CADplans]

Not knowing anything about metal roofing, I put "builder grade" 5V roofing on my first shed,
about 1,600 square feet.
That galvanized steel was about as thick as home AC ductwork,,,
When it was about 15 years old, the problems started to develop.
Luckily, I found some industrial steel roofing, and the "V's" matched.

I screwed it on over 20 years ago,, and the structure has been perfect ever since.

I used the self drilling washer screws, and drilled right through both roofs.
I am positive the roof is much stronger because both layers are there.

AND, luckily, I had a local guy in Bedford VA that sold me the right screws and trim pieces to make the job perfect.

I continue to enjoy it.

Is there any chance you could find metal that can be placed over the existing roof?

 

[grsthegreat]

i had a roofer pull every screw on my 24 yo metal roof on my shop and install a longer, thicker screw with new rubber washer. he said the roof was in too good of shape to replace. last winter all 3 leaks i had were gone.

 

[Midniteoyl]

Kinda looks like my 40x60 barn roof. Mine is 6/12 pitch so it is doable as far as walking on it. I did get a harness and lanyard so I don;t get a runaway for near the edges.

I was worried about wind getting uner the edges so I put pole shed caps on the edges.

I pressure washed it then came the tedious task of finding loose nails and screws that were missing roof joists. How the corrugated steel stayed up there I'll never know. I pulled a gallon or more of very skinny small headed nails and many screws with bad washers.

I replaced non-solid nails and screws with oversized pole barn screws on the holes. All the holes missing joists I patched with a certain clear caulk that doesn't shrink, kind of like silicane but a contractor steered me to it but the name escapes me...

Once I couldn't see anymore holes and snugged all the existing screws up and added many screws I washed it down again.

For the maybe 200 sq foot of rust, I painted with Osphro, a rust restoring chemical on the rusted parts. Once that was dry I sprayed Rustoleum Forest Green on the whole roof. That was about 4-5 years ago and all is good yet.

I did find a few nails and screws missing the joists and a few holes I missed, but hardly anywater comes through anymore.

A fairly reasonable fix that still looks good.

This ^^ was gonna be my suggestion as well. Fix, clean, convert the rust (Ospho) and then paint with a good paint.