Is See Streaks Where The Roof Is Drying Unevenly

If it isn t all the way dry it can still look uneven after another coat of paint.

Is see streaks where the roof is drying unevenly.

Algae growth causes a dark discoloration. Once the algae have infested your roof you ll see black spots begin to form. The algae are usually brown to. This is the first sign that you need to schedule a treatment for your roof.

Although these dark spots and ugly black streaks on your roof may look like dirt mildew soot or mold what they really are is algae. If you look even closer you re bound to notice that the black streaks are everywhere but one place in particular. Black in color which results in a streaked dirty looking rooftop. It can be mistaken.

Why you re seeing black spots or streaks. Stains and streaks can show up easily on roofing and siding over time thanks to a whole host of nuisances including mold mildew and plain ol dirt. This blackish algae creeps it way across neighborhood roofs gradually turning your home s asphalt shingles an ugly dark brown or black. You could spray several light coats of finish over the stain but the adhesion between the finish stain and wood will not be very high.

The algae have a weakness and it s the copper and zinc coating used on the sheet of metal flashing which is toxic and kills the growth. Less paint means a lighter coat resulting in uneven paint streaks on your walls. You ll typically see gloeocapsa magma forming on areas of your roof that don t receive direct sunlight. So unfortunately you re going to have more work ahead of you to get rid of them.

You ve never really taken a good look before but yes it s there. Thankfully the fix to this doesn t involve sanding. If you try to finish over it with a brush some of the stain will probably come off on the brush and give the surface an uneven look. This week s question comes from robert.

If you see streaks in your paint while it s still wet there is a high probability that they re going to be there when it dries. All you need to do is wait for it to completely dry and then apply another coat of paint. The stain did not take well on wood milled with the grain and on cross cuts the stain soaked into the wood giving. This algae growth usually begins as small spots and then eventually becomes visible streaks.

When staining soft maple kitchen doors and drawers from a millworks shop the painter applied a special walnut stain directly to the raw wood. Near the metal flashing that s around chimneys and roof vents. For soot dirt or tree droppings which typically produce only localized discoloration.