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Unfinished Garage Sheetrock

My garage walls have been sheetrocked but not finished. While searching on-line, I have found several that recommend exterior paint. It's thicker, requiring no priming, more temperature resiliant, and more mold/mildew resistant. Opinions??

A. Spruce
Re: Unfinished Garage Sheetrock

It is not recommended to apply ANY type of paint to a bare surface.

How old is the drywall in your garage? If the surface had become brown, then it will be extremely dry and brittle. How does that affect painting it? The dry paper will draw the moisture out of the paint very quickly, resulting in shadows and streaking, it will probably blister as well. The brown color will actually act as a stain and bleed through the paint, because of that, a stain blocking primer would be best suited for the task.

  1. Broom off all walls and ceiling to remove dust, dirt, and cobwebs
  2. The joints and fasteners only have one coat of joint compound on them, so they'll likely be quite hollow compared to the rest of the wall. Apply topping compound to fill depressions, sand smooth when dry.
  3. Apply two coats of a good stain blocking primer. If the walls blister, just leave the blisters alone and allow the primer to dry thoroughly between coats. Once dry, the blisters will likely disappear. Once sealed under the primer, the blisters shouldn't come back.
  4. Apply two good coats of quality paint - Sherwin Williams or Kelly Moore to name two.

If blistering becomes a problem, the walls may need to be skim coated with drywall topping compound. Blisters can be removed and the compound will fill and blend with the rest of the wall.

Hope that helps. :)

Re: Unfinished Garage Sheetrock

Gee Gee,

As usual, Spruce has given out good advice. Follow it! Further, follow the instructions on the paint/primer labels. Most latex stain killing primers state that to get maximum stain killing, you should wait 24 hours for the finish coat.

There are some paints which are self priming, but it is not cost effective to use them to prime themselves. For example, Benjamins Moore's Regal Wall Satin is an excellent primer, but are you going to use a $30 gallon of paint to seal a wall that can be primed with a $15 dedicated stain killing primer? Behr is soon releasing a super premium interior paint which is also self-priming, but again, it will sell for over $30 per gallon.

As to your original question of whether to use an exterior paint in a garage? Does it rain in your garage? Does the sun shine in your garage? All quality interior paints (read: not $8 bucks per gallon) contain mildecides, as do the primers such as Kilz II.

I have always treated garage interiors as if they were indeed interiors. I do prefer to use a higher sheen paint as the finish coat, especially if you are one who likes to wash his car inside the garage. If you do want a really sharp looking garage, spend the time to top off the joints in the drywall. I hate this type of work. You might consider getting in a skilled drywaller to top them off for you. A skilled drywaller will have it done in a short time with a minimum of dust and mess and leave it ready to paint.

Timothy Miller
Re: Unfinished Garage Sheetrock

Howdy, by not finsished do you mean not painted? If it Was taped and sanded you can do additional drywall finish prep more finish mudding and sanding or consider applying a flat white as it will hide a multitude of flaws. I shy away from "kills" primer sealer as its odor about kills me. Exterior paint has more moldiside in it. If you use the exterior paint open the garage door so you get fresh air in while painting.

Re: Unfinished Garage Sheetrock

Timothy, I think you are confusing Kilz primer and Kilz II primer. The original Kilz is a quick dry oil primer which does indeed stink and will give you a real buzz. I avoid its use except when I need its superior stain killing properties. Kilz II is a water based primer which will control minor staining when used according to instructions. It should be adequate to control the brown discoloration on older unsealed drywall.

As to mold control, the mildecide additives in paint last only a few months. The best way to control the mildew is make sure you are not painting over and active spores. Cleaning with a bleach solution is the most common mildecide.

Also, the cheapest and easiest thing you can do to brighten
up a garage is to literally brighten it up. I use self-ballasted compact florescents screwed into the existing utility ceiling sockets. I use a "y" insert to allow me to use 2 100watt equivalent bulbs per outlet. these bulbs only use about 36 actual watts. Home Depot also now carries a large spiral compact flourescent which gives out 300 watts of output for only 67 watts actual watts. It is REALLY bright!

The same improvements hold true for unfinished deep basements. A coat of white paint and brighter bulbs converts that dungeon to an inviting work/storage/play space for only a few dollars. If the walls have never had moisture problems, just use normal interior acrylic primer and paint.

Re: Unfinished Garage Sheetrock

Thanks everyone who replied to my question. I guess there is no way to avoid priming those walls!

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