QUESTION:

HOW CAN I KEEP MILDEW FROM GROWING ON MY NEW EXTERIOR PAINT JOB? WHAT SHOULD I DO WHEN PLANNING THE PAINT JOB?

ANSWER:

Mildew is a black or brown fungus that can grow on, and disfigure surfaces, including paint. While you may not be sure of getting a 100% mildew-free paint job, especially over a long period of time, there are some precautions that can help significantly in reducing or avoiding mildew growth on a paint job. Try to take as many of these into account as you can, when planning your paint job.

1. The Environment: while there isn't much you can do about this, keep these points in mind when deciding how much you want to do with factors you can control: 

  • Warm, moist weather, and absence of freezing temperatures fosters mildew growth

  • Mildew in the area leads to mildew growth (wind-blown spores)

  • Protected areas are worst; sunlit areas grow mildew less

2. The Surface Being Painted:

  • Never paint over mildew: remove it first (for this, see notes below)

  • Bare wood, and oil paint as the previous paint, are bad for mildew, prime these surfaces with quality acrylic latex primer; this includes surfaces scraped down to bare wood or to old oil based paint.

3. The Paint Being Applied:

  • Acrylic or latex is better than alkyd and oil

  • Satin formulas are generally more mildew resistant than flats for stucco walls. A top quality paint likely has more mildewcide than a lower grade paint.

  • Dark colors dry out faster because they warm up faster (dew, rain) so tend to            support mildew less.

  • Use mildew-resisting additive only if recommended by the paint manufacturer

4. Applying the Paint:

  • Two coats are better than one.

  • Avoid painting when breezy, especially if mildew is seen in the area. When removing mildew from an area to be painted, you need to allow a bleach solution to stay on the surface for at least 20 minutes, or the mildew will not be killed (even though the color disappears), and it can grow back before long. To treat a mildewed area, use a 3:1 mixture of water and household bleach, respectively; and leave on for 20+ minutes, reapplying as it dries. Be sure to include a 1-2 foot margin around the affected area, and protect your eyes, breathing and skin, and nearby plants, during application and rinsing. Rinse off the area thoroughly; then wash the area and rinse again.

QUESTION:

WHAT IS THE BEST METHOD FOR REMOVING A PIGMENTED STAIN FROM REDWOOD SIDING. WE ARE TRYING TO RESTORE THE REDWOOD TO IT'S NATURAL STATE SO WE CAN PRESERVE IT WITH A CLEAR PRESERVATIVE? 

ANSWER:

There is no easy way to do this, as you might imagine. Consider these possibilities:

1. Chemical remover. Paint remover can be effective but tedious. Apply stripper in a heavy coat by natural bristle brush; protect skin, breathing and eyes with chemical resistant gloves, goggles, overalls, and an appropriate respirator. Do small areas at a time, at 10 square feet max. Allow to stay on for 20-30 minutes (time may vary due to weather conditions), then remove the softened stain with a 3" spackling blade, onto a disposable drop cloth. Protect plants, and keep children and pets away. Then move to another area. You'll probably have to sand the wood after it dries, to get the last of it off, and to get the color you want.

2. Sanding. Sand the wood with the grain, using #100 - #120 grit production or aluminum oxide paper. A 3" or 4" belt sander will work well for bevel siding if have the strength to hold the sander. Use care to sand the wood evenly and not dig into it. Wear goggles, gloves and a quality dusk mask. Power washing and sandblasting are other possibilities, but with redwood, these would have to be done by a pro who is very experienced with doing the procedure with redwood.  

Be aware that you will probably have to reapply the clear material every year or two to maintain appearance.

QUESTION:

I HAVE SEVERAL CONTRACTORS QUOTING ON PAINTING THE EXTERIOR OF MY HOME. HOWEVER, WHEN QUESTIONED ON WHAT IS THE BEST METHOD TO APPLY THE PAINT (HAND BRUSH OR SPRAYER), THEY ARE AS MANY OPINIONS AS THERE ARE CONTRACTORS. THE EXTERIOR SIDING IS HARDBOARD.

 ANSWER:

 Basically, both spraying and brushing are fine, so long as the paint is put on at the proper spread rate (sq. ft./gallon). Spraying will provide a smoother appearance, and the painter has to be careful about getting a full coat onto areas that are next to areas that won't be painted, so careful masking must be done. Some people think sprayed paint will not adhere as well as if brushed, but we have not seen that, so long as the surface has been properly prepared.

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2010 Smith Paint
2875 Cherry Ave. Signal Hill, CA  90755
562.595.4761