Garage built in hillside sweating

GPintheMitten · Mar 4, 2016

I'm having a hard time picturing the building with a concrete ceiling and metal roof dripping condensate into the building. I understand it being built into a hillside but can't figure out the ceiling and roof configuration.

Billrog · Mar 4, 2016

A roof vent is not going to stop the condensation in this case. I think Deere Dude has the best answer & since it's under ground the ceiling may only have to be done. To vent out you would also have to have air vented in lower down. If the barn drs. were sealed heating the space would be the best answer to eliminating the condensation. By the explanation it sounds like the metal ceiling was put in over the forms to hold the concrete until they were taken out ?

rickyb01 · Mar 4, 2016

Ok guys I really appreciate your comments. Pictures are worth a 1000 words but I don't have any. I have a offer on the home but have not heard back from my realtor. I have no way of knowing how this bomb/storage shelter was built. It looks like they dug into the side of a steep hill and poured the slab and blocked up the walls. Your guess is as good as mine on the roof but everything is covered except the front which has two swing out barn doors and a metal front door beside barn doors. The barn doors are not sealed very good. On top of shelter they have a fire pit and chairs and it looks out over a river. I don't know how I would get a hole thru concrete top for whirlybird? How would I get vents on bottom? I really want to utilize the space and if I get the property. here are some off the internet

ruffdog · Mar 4, 2016

I have lived in a underground home. Never ever open it up on a warm and humid day. If the concrete is cold and you let that humid air in, it will sweat just like a cold glass on a hot humid day. Even my Steelmaster building that is on a slab will sweat the floor on the wrong days. Nothing wrong with it, you just have to know when to open and when to keep it closed.

Tractor Seabee · Mar 5, 2016

Unless you are going to heat the space, insulation is a waste of time and money. You need forced ventilation operated by a humidistat. A blower at the ceiling line on the door end, ducted out through a back-draft damper with another inlet grill with back-draft damper at the floor line. For the size you need to run a duct along the ceiling with several inlets to assure full circulation. Fan and duct sizing is a mechanical engineering solution I will bow out of lest I mislead someone. Those using shipping containers for storage have the same problem

Ron

2458n · Mar 5, 2016

I have owned a garage built during world war 2. It is in the ground on three sides with two 9ft. garage doors. 10 to 12 inch thick concrete roof with slope towards the back. I have painted the inside with white water block paint. Have used fans and heat. Might have done more, but everything did not work. It is a rust pit. Snap on boxes ruined. tools ruined. TV and stereo ruined. Car and motorcycle ruined. Kubota has set outside under cover for 34 years. Do not buy this property at any cost. A good dry barn would have saved me thousands. I am in Ohio so the weather changes daily.

Howling · Mar 5, 2016

ruffdog said:
I have lived in a underground home. Never ever open it up on a warm and humid day. If the concrete is cold and you let that humid air in, it will sweat just like a cold glass on a hot humid day. Even my Steelmaster building that is on a slab will sweat the floor on the wrong days. Nothing wrong with it, you just have to know when to open and when to keep it closed.

My shop is concrete slab on bedrock and partial concrete walls. Stays naturally cool way in to the summer. But the outside hot and humid air cause condensation and rust on everything in the shop. Now I keep it closed up and starting late spring/early summer leave air conditioner on low to to keep the humidity down. The electric bill is cheaper than the water/rust damage to my tool and equipment.

GPintheMitten · Mar 5, 2016

Well, you could still buy the property but store something in there that likes humidity. Maybe grow mushrooms. Seriously.

But may want to plan on building a new outbuilding.

KennyG · Mar 5, 2016

Property looks great even if the storage unit turns out to be useless. I would start out by cutting vents in the bottom of the doors. Is the front wall poured or frame with stone facing? To vent it at the top, I think you are looking at concrete work, but that's not a killer if you rent the right tools. I would suggest cutting a good size hole in the top/deck and buiding a small stone or brick pedestal. You can open the sides of it as vents and put a top on it that would become kind of a permanent table.

Humidistat fan as recommended could be used in the top vent. Do you have power there?

Oh, yes, and build a big pole barn somewhere else on the property. We love pole barns.

ruffdog · Mar 5, 2016

The ground is cool in the summer and warm in the winter. That is why people built earth homes. If you think you can pump enough air through that boathouse to make it dry on a humid day, your nuts. The moisture comes from the air that you want to pump through it. You will never warm the earth around it enough for it not to sweat on a warm spring day with the doors open. Keep an eye on the outside humidity and temp and learn when you should or shouldn't open it up. Work with it instead of fighting it.