inside leaking roof on my new woodshed all steel construction?

  • Advertise with us

« back to Focus on the Workspace forum

Forum topic by SCOTSMAN posted 12-07-2012 08:00 PM 3278 views 0 times favorited 34 replies Add to Favorites Watch
View SCOTSMAN's profile


5849 posts in 3582 days

12-07-2012 08:00 PM

I have the most awful condensation dripping from the roof of my new all steel workshop storage shed.I have been told that applying a few thin rolls of polystyrene insulation material will stop it how thick does it have to be any other information wood be most helpful too? I am sure it’s not a leak as the whole roof inside is dripping.Alistair

-- excuse my typing as I have a form of parkinsons disease

34 replies so far

View chrisstef's profile


17381 posts in 3003 days

#1 posted 12-07-2012 08:06 PM

I wonder if a small dehumidifier would help out Alistair? In terms of the pS insulation i cant imagine anythign over 1” would be needed.

Were the roof seams welded? Maybe they burnt through a small portion?

Just tossing ideas around.

-- Its not a crack, its a casting imperfection.

View MrRon's profile


4764 posts in 3240 days

#2 posted 12-07-2012 08:12 PM

A spray-on insulation applied to the roof might work; the type used on mobile homes. Condensation is due to warm moist air striking a cold surface.

View Dick, & Barb Cain's profile

Dick, & Barb Cain

8693 posts in 4296 days

#3 posted 12-07-2012 08:15 PM

I had a friend who built a ice fishing dark house for spearing fish out of aluminum sheets.

When he lit his small heater, condensation would build up, & freeze it would melt, & drip off of the sheeting.

-- -** You are never to old to set another goal or to dream a new dream ****************** Dick, & Barb Cain, Hibbing, MN.

View Built2Last's profile


234 posts in 3474 days

#4 posted 12-07-2012 08:23 PM

This is the reason they build most storage building out of aluminum, it doesn’t do that. With steel, you would have to keep it bone dry, so I don’t think a dehumidifier would help. If it got the humidity low eoungh to stop the condensation, you lumber may get to dry. You best soulution, is to put fiberglass insulation on the top, preferebly the kind with a plastic backing like they use on Butler type buildings. I built an 80 by 88 shop with steel roofing and had the same problem, ” like a rain forest up in there”. You can also spray the foam type but here its hard to find someone to spray a small building. Good luck!!

View Don W's profile

Don W

18711 posts in 2564 days

#5 posted 12-07-2012 08:25 PM

It needs to be thick enough to keep the warmer moist air from making contact with the metal. I would suggest talking to someone who knows your climate conditions for what you need.

I think mrron is on the money but don’t know how thick it should be.

-- - Collecting is an investment in the past, and the future.

View teejk's profile


1215 posts in 2681 days

#6 posted 12-07-2012 08:25 PM

condensation issue. I was told NOT to spray foam since the steel and material expand/contract at different rates leading to pockets of moisture that will cause a premature failure of the steel. cut in gable end vents to start (warm air seeks cold air). an industrial ceiling fan (pretty cheap) would help also I think.

View patron's profile (online now)


13603 posts in 3337 days

#7 posted 12-07-2012 08:38 PM

most old tin roofs just laid the tin on cross stringers

would rot the top of the wall plates and stringers
from the condensation thru the metal

the way to stop it
is why they put tar paper
under the metal
so the water goes out
without catching on the stringers or wall plates

like a sub-roof for the water

many old barns were so open
that it wasn’t a problem

-- david - only thru kindness can this world be whole . If we don't succeed we run the risk of failure. Dan Quayle

View Don W's profile

Don W

18711 posts in 2564 days

#8 posted 12-07-2012 08:42 PM

When I built my shop I was told to plywood the roof instead of using strapping because it would prevent condensation. Its worked so far.

-- - Collecting is an investment in the past, and the future.

View HorizontalMike's profile


7756 posts in 2910 days

#9 posted 12-07-2012 08:56 PM

I’m sorry to hear that Scotsman. Is it too late to add a roof vent? On my metal shop I have an 8ft long vent along the gable. It has a chain pull to open and close the vent from the inside. Just a thought.

Similar to one of these:

-- HorizontalMike -- "Woodpeckers understand..."

View 404 - Not Found's profile

404 - Not Found

2544 posts in 2966 days

#10 posted 12-07-2012 09:40 PM

Any chance you could post a photo Alistair?

There’s a number of things you could do, but without knowing the construction it difficult to know where to start.

Also, would you be able to take the roof off in the spring or are you trying to avoid that?

View teejk's profile


1215 posts in 2681 days

#11 posted 12-07-2012 10:11 PM

was thinking the same thing Renners…without knowing the structure it’s hard to make suggestions. Cheapest solutions though would be to get the warm moist air outside (warm air moves to cold air) via gable vents or drive it back down via fan(s).

surprised he doesn’t have a ridge vent on the top (pretty much code now I think)...I have it in my steel building along with ventilated sofitts that creates an automatic air flow.

View juniorjock's profile


1930 posts in 3762 days

#12 posted 12-07-2012 10:21 PM

Lots of good stuff here. I’ve had the same problem. Cold meets heat = condensation. I installed some R13 insulation and I think that has taken care of it. I do pull it out in a couple of places to check it every now and then. Just wondering if a vapor barrier would help or would that be worse because its on the paper side of the insulation??

View HorizontalMike's profile


7756 posts in 2910 days

#13 posted 12-07-2012 10:28 PM

You may be on to something there. Insulation will sure help minimize temperature fluctuations inside, but one still needs to vent air on those days of extreme variation. I think I am using something called Solartex, or the like, on my shop. It is only 1/4in thick, has a vapor barrier, a radiant heat barrier, and 1/4in of fiberglass insulation. In south Texas this is perfect! In the middle of winter I can heat my 24×30 shop with a single 1000w baseboard heater. I get up to mid-60s within a couple of hours.

-- HorizontalMike -- "Woodpeckers understand..."

View DrDirt's profile


4424 posts in 3739 days

#14 posted 12-07-2012 10:36 PM

Good Points, I have seen best results on metal buildings (Morton is the big company here in Kansas) but there are others, is to go with the spray on foam, as there no water trapped anywhere.

Allistair didn’t mention what he was using for heating. If it is kerosene or Propane, there is a lot of water there. So an option depending on how warm you like it, and the kwHr rate for electricity is to use an electric heater.

-- “The two most important days in your life are the day you are born and the day you find out why.” Mark Twain

View SASmith               's profile


1850 posts in 2983 days

#15 posted 12-07-2012 10:43 PM

Around here most pole barns have something like this to prevent condensation. It is less than a half inch thick. Not sure of the R factor (low I’m sure) but it does prevent condensation.

It is typically installed between the purlins and the roof metal.

-- Scott Smith, Southern Illinois

showing 1 through 15 of 34 replies

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics