Exterior paint on interior?

[Nubs]

I want to paint the interior walls of my garage.

The garage is under the house, has concrete block about half way up, and the rest is drywalled. Originally, the builder rolled/sprayed on a thin coat of mix, and dragged a roller through it.

I had painted interior paint on the walls. Now, since washing the vehicles inside after many years, the mud is peeling in places from the drywall. The garage is not heated, but stays warmer than the outside air temperature.

Can I use exterior paint on the drywall? Do I have to use a primer on bare drywall where the mud has come off? Should I primer all areas, even the area where the mud/texture has not come off?

One last point. Can I use exterior paint on the concrete block? Should I prime the block, which has never been painted?

Many thanks.

[jJim McLaughlin]

And when you went to two separate real paint stores, Sherwin Willians and Benj. Moore, what did the professionals there tell you?

[Nubs]

Being I can't get to a store until the weekend, I figured I'd see who has any real first hand knowledge.

Thanks for sharing yours.

[ransley]

Just use the exterior paint one coat or 2 to cover, but mud pealing sounds like moisture is afecting it

[hallerb]

i have used exterior on interior for mold control, then added extra anti mold material.

i couldnt tell the difference between interior and exterior and some paint is marked for both

[jJim McLaughlin]

No need to be snide.

I could just do what too many folks on here do, make it up to stroke your ego.

Try a telephone call to a paint store if you can't get to a real paint store. And try a real paint store, not a strip mall outlet catering to home owner harry types.

And lose the attitude.

[Robert Barr]

What 'attitude'? Who the f(*&k are you supposed to be?

[jim]

Exterior paint is not durable for inside use. It may chalk excessively and/or the paint would not stick to the surface if it needs to be repainted. Exterior paint also contains mildewsides/fungicides that may smell when there is high humidity. It can even pose a health hazard due to the greater concentration of these mildewsides that are not normally used inside. Exterior paint used indoors may also worsen allergies.

[ransley]

Its for a garage wall, exterior is plenty durable and the statement about not sticking is bs if the walls are now flat. Your concerns are not based on experiance.

[Stormin Mormon]

"Experiance". A word that should be in the dictionary, but isn't. Yet.

[DerbyDad03]

Since a garage might be in a somewhat grey area between being "interior" and "exterior", may I suggest that you Google something like "using exterior paint inside" and read all the various reasons that a multitude of sources say it shouldn''t be done.

For each reason not to do it, see if that reason fits your circumstance and decide for yourself. It appears to me that you could make an argument either way when dealing with an unheated garage.

[cshenk]

"Nubs" wrote

For a long lasting finish, yes you need to prime the drywall. All of it for the best finish. Be sure all the mud is off but dont get it too wet in the process. Let completely dry, then prime and use a paint over that meant to be 'washed' (exterior will do)

Yes, and again prime first. You may find the best to use here is stuff sold for basement cinderblock. It's thicker and easier to add to a pourous concrete block. It will likely take 2 coats with a thicker roller.

If a brand name helps, last time I was involved with this, Mom got only Sherman Williams (sold at sears). I am sure there are others as good, but this one worked for us in a somewhat similar need.

[cshenk]

I think an exterior paint will be fine for an unheated garage and it will be more water resistant since he's washing cars in there to the point of mud spatters on the upper drywall. I wouldnt however use just any exteror on the cinderblock (so I am assuming the cement blocks are) as it would require possibly as many as 4 coats to deal with the porous nature.

[Joseph Meehan]

The problem I can see is that many outdoor paints are self cleaning. That is they are designed to slowly erode and have the rain wash off a little each time. Inside you are likely to end up with a powder on the surface. Someone brushing against it will find it will rub off onto their clothing.

You need to check with knowledgeable staff. You can find good and bad staff anywhere, but you are more likely to find knowledgeable staff at a real paint store.

[clifto]

Does it mean anything like "experience", which is?

[Buck Turgidson]

First, I'd probably stop washing the cars in the garage. That might be the root cause of the problem.

Secondly, I'd go with an oil primer, and an oil satin. Benjamin Moore probably still carries oil-base in gallons.

[jim]

Nope - based on common sense and the manuf. guidelines.

[larry moe 'n curly]

If it wasn't the garage, I'd worry about the anti-fungal chemicals in exterior paint.

I searched for "exterior paint indoors" and found this from the PaintQualityInstitute.com:

"Use cauti "Paints that are dedicated for exterior use have concentrated mildewcides and fungicides that could have heath risks if used indoors. Plus, exterior paints have more VOC's, which means the paint will have a potent smell when compared to its interior counterparts.

"Exterior paints, especially acrylics, are designed to fast dry and resist the worst that the environment can offer. Because of this, exterior paints won't easily flow out smoothly on a surface and will more difficult to use. Many quality interior paints have the same great attributes as exterior paints without the health risks or problems of exterior paints."

[Bonnett Decorating]

Retape and spackle as needed. Spot prime repairs and prime block. My preference is an acrylic primer like BM Fresh Start. Top coat with paint of choice. My preference is BM Super Hide in bone white. It's a second line interior paint, more than good enough for a garage, covers well and is priced right in 5 gallon pails. FWIW YMMV