Sweating metal building

[hilld]

I recently finished a 30x50 metal building and have had severe sweating problems in the building, the metal in soaking wet. I am in Oregon, and we have had a rather unusually wet winter this year.

My building is completely tight, and insulated R-19 in the walls and R-30 on the ceiling but I am in the process or adding a forced ventilation system to it as well as a heat pump to control temperature. The floor is a 6" concrete slab (no vapor barrier), I am looking for input on how to solve the problem. Will an ERV system that removes humidity be my solution?

Thanks,

Derek /forums/images/graemlins/confused.gif

 

[Cord]

I presume things are first starting to warm up out there. Often this condensation will occur in the spring and then dissappear when things finally warm up. Turning the heat on will help pull the condensation off the metal on into the air.

It's unfortinate there is no vapor barrier under the slab. Did you use one over your insulation? If not, then you'd better get one installed or your insulation will be sopping wet.

 

[Highbeam]

Something's funny, you say that the sides and ceiling are insulated yet you have wet metal. How can this be? Is the outside wet? Did you somehow reach though the insulation to touch the inside of the metal and find moisture?

 

[dooleysm]

I agree with highbeam. You said you insulated your ceiling. I take the ceiling to be the bottom of your horizontal truss joists. If that's where your insulation is and you have a metal roof that is not vented, I would expect moisture up there. You will need to address that once you have your planned HVAC in. You will need to vent your attic area somehow.

 

[hilld]

If I pull the insulation (kraft faced fiberglass) away from the metal, it is soaked. There is a vapor barrier (double bubble foil) against the roof, followed by unfaced R-21 (total R-30) insulation on the ceiling, R-19 faced glass against the walls. Water is not leaking through the metal. The building has gutters to prevent the roof runoff from coming down the side of the building.

I have been told various things such as the concrete hasn't cured yet (it has been 4 months since the slab was poured), to we are not sure why your building is sweating.

It is completely sealed, I have been researching HRV's and ERV's to exchange the air in the building, the one I am looking at is a FanTech ERV, which will change the air in the building every 2 hours and according to them should solve my problem. I just want to make sure that if I go with them (about 800 smackers) with my labor, that it is money wisely spent. The building will serve as our photography studio and will be sheetrocked, don't want to have mold problems coming later.

Thanks for all the help.

Derek

 

[MrJimi]

</font><font color="blue" class="small">( I recently finished a 30x50 metal building and have had severe sweating problems in the building, the metal in soaking wet. I am in Oregon, and we have had a rather unusually wet winter this year.

My building is completely tight, and insulated R-19 in the walls and R-30 on the ceiling but I am in the process or adding a forced ventilation system to it as well as a heat pump to control temperature. The floor is a 6" concrete slab (no vapor barrier), I am looking for input on how to solve the problem. Will an ERV system that removes humidity be my solution?

Thanks,

Derek /forums/images/graemlins/confused.gif )</font>

Like ya said in your first posting? Ya dint seal your floor?
A vapor barrier is extremely important in this building! It stops water/ moister from coming in and rusting your stuff
I, my self would NEVER do without it?
Jim /forums/images/graemlins/smile.gif

 

[hilld]

This building has no attic, the trusses are all metal and are more like an A-frame. It is completely open. I have reached behind the foil and yes, there is moisture.

 

[hilld]

The slab does NOT have a vapor barrier under it, can I add one now by using something called dricore (www.dricore.com) or some sort of epoxy sealer?

 

[hilld]

Here are some images of how the roof is constructed.

 

[inveresk]

Derek, if you want to PM me details of the construction of your walls, roof and floor, I can carry out an interstitial condensation analysis on a computer programme I use for the purpose. I can also test some possible solutions using the programme and advise you what works and what doesn't.