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I've been getting some calls lately for exterior painting mostly because the homeowner has mildew growing on the house. One thing I was noticing is that most of the problems were on houses that were stained. Is there any correlation between the 2 or is it coincidence?

Also, do those mildew resistant paints/stains or additives really work in preventing it from coming back? I use it to make the homeowner happy, but am skeptical as to its usefullness.
 

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the houses with stain usually have a more ruf surface
leaving more texture providing more better area for mold to
cling to,? thats my guess? Never went back to see if the mildew addatives
really work,sounds bad but I never got a call ? ...dr
 

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I actually had a paint rep tell me not to ever add those little mildew packets to paint because it effects the performance of the paint and if it fails then they're not liable because you added the packet. He said they add plenty of mildicides (sp?) to exterior paints.
I've had so many homeowners insist I mix a few packs in, just to be sure, they seem to love that stuff.
 

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I understand that the oil that makes up most stains is actually a preferred food for many strains of mildew. That plus a shady, damp area and you have a perfect picnic for the little monsters. However, I have seem mildew sprout in places where I can find zero reason as to how. I also heard that those packets, while not completely worthless, have very little effectiveness. If it makes the customer happy though...
 

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Mildew is a saprophytic fungus-- it consumes organic materials. Oil base products contain more organic compounds than latex products. In addition, oil products are slower to dry, which allows mold spores a longer period to attach to the film. Oil products basically are like a buffet for mold and mildew.

A mild bleach solution with powdered detergent will clean it off. However, too much bleach can also remove the stain, so you need to be careful.

For severe mildew problems we use TWP Mildew Sealer.

Brian Phillips
 

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Pete's,

A fungicide will migrate out from a finish while it is curing and even beyond that time. The tendency to find the path of least resistance means the weaker the finish integrity, the faster the coating is going to lose its mold fighting capability. Once a film cracks, or again while the product is curing, much of the fungicide present is going to get washed away. Now couple that with the fact that a) stains don't form the same type of barrier as a paint and b) most exterior wood stains are still oil based and you are absolutely correct in your assumption.
 

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I've done many solid oil stain jobs on homes and never had much of a mildew problem. I did my sisters picket fence with Cabot's OVT in bright white two years ago - and still not one spore of mold! What I have found to be most important is how thoroughly you pressure wash your substrate. I 'soft' pressure washed this lady's home a year - which had awful mildew - the paint job was horrible - it was acrylic latex solid house stain - but very loosely adhering. I came back to this house - and noticed the mildew came back with a vengence - and realized the substrate was just never really 'nuked' well enough - and even though I 'soft' washed the exterior, the mildew was beneath the latest paint film and cracks and came right out again. If you painted this home - it would have a severe mildew problem.

That being said - I painted this home 2 years ago - everything was resided with factory primed trim and clapboards. then they let it sit for 22 months - and let the tannins bleed out - they were strapped for case. So I went to work with TSP and bleach and scrubbed the whole house from the ground to the tip of the gables - and then used 2800psi and blasted it all off. Everything was clean - even the artillery fungus was history. So I reprimed the clapboards with P&L's exterior oil primer and one coat of accolade on top of it. But since the couple was strapped for cash and didn't know what colors they really wanted for trim - we decided when I re-primed the trim - that I would tint to a color they were thinking about. And that's how I left that job. 2 years later - there is not one speck of mildew on the clapboard - but some pieces of trim, even though they were primed yellow - now look totally black from mildew growth!
 

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AA & Brian are absolutely correct. Oil based products of any kind are significantly more prone to mold growth. It is food. Please do not prime a moldy bathroom w/ any Kilz or Coverstain. EVEN if you have "removed" the mold. A latex primer is the way to go.

Look @ this link. This product is amazing and is pretty easy to use and eco friendly.
www.moldavenger.com/

Also, Brian is on to something "ya'll". TWP (Total Wood Preservative) is quite definitely one of the best products on the market. It is made by Gemini, and their line will even deter termites from substrates like cedar fencing.

Mildewcides, by the way........ Most premium products have the legal limit allowed by the gov't. IF you add in your paint, I suggest only adding to your topcoat if application allows for that. Not doing any good in your 1st coat, as they primarily work on surface growth.
 

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So how does Kelly Moore paints compare to Benjamin Moore paints? And how come it's only on the west coast?
Well, I'd like to think we compare very well as far as quality in the bucket. I think we have specialty lines designed for the applicator/painter. Kelly-Moore is the professionals choice for the most part in the Bay Area/NorCal, where Mr. Moore founded the company in 1946.

We are as "far east" as Oklahoma. :) We really have focused on markets we are already in and solidifying that. Our focus as a consumer is the pro painter, and we really understand how to help you make $$$. I saved a customer $1000K on an interior new residential w/o even a sweat. His client wanted BM, but really couldn't even see not going w/ Kelly-Moore. We used all our premium products also. Thx for asking. I hope that answered your questions.
 
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