Thread: AARG steel shed, condensation and rust

Originally Posted by Yonnee

I'm going to contradict what Malb stated, and recommend some sort of sizilation. I have it in my current shed, and do not get any condensation drips whatsoever. Even on the nights/mornings where the pergola/deck looks like it's raining inside, the shed is still bone dry. Same with factories I've worked in. The only drips we got on the stock in the warehouse were where the skylights were... no sizilation.

I have polycarbonate sheeting on part of my shed roof, and it so far has not shown any sign of drips or condensation on the inside. The shed also has Aircell insulation. I guess that most people install roof sarking of some sort or other for two reasons: to help prevent the ingress of water from faulty/damaged roofing material when it rains, as well as condensation that may occur underneath the iron roof as well; and also in most cases today, for some degree of insulation, depending on the type of material installed.

If there is any doubt that there may be moisture in the air in your shed, then it would be wise I believe, to provide some sort of barrier protection for the equipment at risk. As far as water drips are concerned, if they are a problem, then don't put any machinery beneath them.

JMHO FWIW

IMO a lot of this problem relates to the pitch of the roof and possibly the profile, with custom orb being the best. My open machinery sheds and locked workshop at Oberon are corrugated with a steeper pitch and don't drip at all. The shallow pitch polycarb roof on the open deck drips like crazy. None have sisalation.

I'm very surprised to hear Malb's father had a dripping roof with sisalation. An exhaust fan from a stove which vents into the roof space might explain the problem.

Woodie, are your tools rusting because they are under the drips? If not, then you have a ventilation and/or rising damp problem. If so, then lifting the roof sheets to install standard sisalation is the way to go. That's what it's designed for. IMO, Aircell under the steel will not do much more than the regular sisalation.The Uni of SA did some studies showing that the stated R rating of blanket insulation is reduced by over 50% because of leakage against the purlins and the metal roof itself. Aircell is designed to droop between the purlins to achieve anything like its claims. Most of the insulation comes from the reflective coating so IMO you might as well save your money.

Another approach might be to tech screw villaboard sheets under the purlins which will catch the drips and also provide a fair degree of insulation and airflow between ceiling & roof.

Mick

The tools are rusting due to the moisture in the air and due to the drips from the steel roof. I have moved the machinery away from the drips, but the water that drips into the shed increases the moisture in the air and then the tools start to rust. I am considering lining the shed with 6 mm or 12 mm ply with insulation between the walls and the new lining. Will have to move everything from around the wall to line the shed. I will probably undertake the work during the Spring, so I can move some of the machinery out of the shed. Until then I would like to put silver glide over the steel areas of the machinery. I also hve a roof vent sucking air out when the wind blows (just of late the wind has been realy blowing gale force winds)

Thanks for all your suggestions.

G'day Woodie2, you've gotta ask yourself where's the moisture coming from? If you've got a roof vent and reasonable air flow, then you shouldn't be getting that much condensation that its dripping from the roof.
My guess would be that your floor is not laid on plastic and thats where the moisture is coming from. The importance of having a moisture barrier under your floor cannot be stressed too highly.
What to do about it? There may be some type of sealer you can coat the floor with, and I'm sure someone out there will be able to advise us in that regard. But for mine I'd empty the shed, lay black plastic and pour another slab over the old one. Scary expensive stuff but thats my background, I love concrete.

Geoff.

You might try this product Instant Pro MOISTURE BARRIER before committing to an new slab. You can coat over it with some sort of paving paint.

Mick

There you go Woodie2, I'll bet if you try that your problems solved.
Good one Mick.

Geoff.