How Too ?

[Culvert]

Hey Guys,
Have a question on how to get my shop set up. I have a 30'-40' steel shop, on concert foundation. 2x4 construction with metal siding & roof. It has dirt floor & no insulation. Right now I have issues with the roof getting condensation & dripping on everything. Due to the water problem I only have a couple lights & 3-4 wall plugs cause I'm afraid of electricuting myself when they get wet.
Anyway.....how do I stop the condensation? Can I throw in some insulation & vapour barrier & this will stop or do I need to do more?
Thanks for the help.

Really like the shop but right now it is just a big old cold garden shed!!

 

[maxwell]

what is the roof constructed of now?

is it just the metal on the trusses?

if so check that the panels are overlapping eachother and all need to be caulked UNDERNEATH the joints not at the joints. also every screw should have cauking.

where does it leak from?

is it just building up on the underside from changing temperatures and dripping or actually leaking?

 

[Culvert]

No leaks from rain or snow melting. Just temp chaning causes condensation inside. It is steel sheets on strapping right on top of rafters.

 

[maxwell]

hmm. sometimes steel roof manufactueres require the steel roof to be installed on a solid deck with an underlayment..

another option would be to create an attic and get some positive ventillation going accross the ridge.

could also consider running a dehumidifier.

 

[Bogger]

Hmmmmm.... I've got the same set-up..... dirt floor, tin walls & roof over 2x6 stud. I've never had condensation issues, I'm currently in the process of insulating and plywood sheeting the interior.... Are you cranking heat inside when it's cold out????? Mine is currently unheated but once it is insulated and sheeted I will be installing a gas furnace..... I can see condensation if your heating the inside when it's cold but otherwise I'd guess it's water getting in somewhere....

 

[maxwell]

its just the temp change on the metal decking. think about a cold pop can. how it forms condensation on the outside. need to get air moving over the surface

 

[Summiteer]

cross ventilation near the peak of the roof would help. you'll need that if you finish inside anyway. Exhaust fan below future ceiling height with an inlet vent across the shop from it should solve your problem and you'll want that after you finish the inside anyway.

 

[Culvert]

Thanks for all the info guys. It is not heated. Just a large 30X40 structure. It is set back into a stand of pines so that may be the cause of the cooler temps?? All the soffits are wide open at this time aswell so it should be getting good airflow.
Just want to know the best way to complete shop. Some contractors also said I need to remove the steel then plywood sheet the roof and cover completely with felt wrap. Then replace metal roofing. Then others just tell me it need airflow & to be properly insulated w/ vapour barrier. Just dont want to get it all insulated & find it still gets wet on the inside.

 

[Bogger]

Thanks for all the info guys. It is not heated. Just a large 30X40 structure. It is set back into a stand of pines so that may be the cause of the cooler temps?? All the soffits are wide open at this time aswell so it should be getting good airflow.
Just want to know the best way to complete shop. Some contractors also said I need to remove the steel then plywood sheet the roof and cover completely with felt wrap. Then replace metal roofing. Then others just tell me it need airflow & to be properly insulated w/ vapour barrier. Just dont want to get it all insulated & find it still gets wet on the inside.

As long as you leave your attic area ventilated to the outdoors....screened soffits ect... then I figure you should be fine. Like I said I'm currently wide open on my soffits with good airflow up along the peak as it is vented... when I sheet the bottom of the trusses I will install two vents to the outter walls.

 

[maxwell]

yah that ridge vent like bogger shows or 2 gable end vents would work also.

but i would take what the contractor said and do that.

lay down some sheathing then a felt.

throwing up a vapour barrier isnt the solution then water will just be trapped behind.

 

[Culvert]

Thanks Bogger,
Thats what mine looks like now. I have stopped & talked with several farmers in the area & none of them have issues with moisture. There shops are out in the open areas however & getting sun on them & lots of airflow. Mine is set back in a stand of large pine, spruce trees & shaded most of the time & only gets wind from the north.

I'll get it insulated & sheeted inside & see what happens. If its still a problem I will pull the roof & sheet it then.

 

[Summiteer]

Is there a fair bit of moisture in the ground? Could be when the building heats up in the day, evaporates moisture out of the ground inside the shop and at night when tin cools first, moisture condenses on cool tin and drips...again, ventilation should alleviate that problem as well.

 

[ferniesnow]

Different strokes for different folks! The metal manufactures recommend different ways of putting on metal rooves; some want sheathing, 30# roofing paper, and strapping every 16" and others want just strapping on the trusses. IMHO, you shouldn't have to pull the metal and start over.

Address it sooner than later as you may notice the bottom of the metal starting to rust. If it does, sand it lightly and repaint it with a spray can of primer.

As Bogger pointed out, get the insulation and poly in the ceiling. Don't forget the insulation baffles at the exterior walls to keep the insulation off the metal above the top plate. You need circulation from the soffit into the attic cavity and out. Besides the ridge vent you should have vents in the gable ends. Tape the poly with "tuck" tape and then look at what to use for sheathing on the ceiling.

If you run into problems there are lots of guys on here with the information to help you out. Good luck, fs

 

[Culvert]

Yes to Summiteer... .with the dirt floor there is lots of moisture seeping under the foundation and coming up inside the shop. This condensation is only an issue during the rainy fall & then agian in spring with the snow melt.
Now what to do??? Finish the floor first? Insulate the roof? To many things and no damm money for any of it!

 

[Bogger]

Yes to Summiteer... .with the dirt floor there is lots of moisture seeping under the foundation and coming up inside the shop. This condensation is only an issue during the rainy fall & then agian in spring with the snow melt.
Now what to do??? Finish the floor first? Insulate the roof? To many things and no damm money for any of it!

Start with airflow.... this will fix the moisture.... insulation and crap will not be necessary until fall, you have time......

As suggested I'd cut the gable ends and install vents Cheap & easy...
are there any windows in the shop??????? if so keep them open for extra air flow.... maybe consider throwing in a ceiling fan (temporary or perminent)...gotta figure out and fix the condensation problem and safe out the electrical before considering insulation/sheeting ect

 

[maxwell]

concrete