I am having a paint failure on a newly painted house: East face, older cedar siding primed with oil primer and 2 coats of acrylic latex top coat, hand brushed. The paint is blistering, and began to fail within one week of application, and it only occurred on the East face of the building.
The house is not under a great deal of heat load, being somewhat shaded and located in Seattle. The building sat drying in late summer sun for a good period. Some of the siding is flat-grain, rather than quarter-sawn material, and these boards are more apt to be blistering. The roof is vented with a continuous ridge vent, and soffit vents below. The failing wall is on a gabled side and therefore has little interaction with the small attic space.
I want to try siding wedges beneath the clapboards to encourage air passage behind the siding. I believe I saw them somewhere in Fine Homebuilding, but my research comes up blank for a source of product. Does anyone know who builds a siding wedge? Any opinions on their performance? Any htoughts are greatly appreciated. Gleno
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Before venturing an opinion, it would be good to know a few things. Did the cedar sit out in the sun before it was primed? How long? Did you sand before priming? Is it backprimed?
I ask because wood that's been exposed to the sun for two weeks or more must be sanded before it's painted. The UV destroys the lignins that hold together the fibers, and unless that destroyed layer is removed, the wood will not hold paint for any period of time. That said, it should still hold paint for 2 to 5 years. Yours went south kind of fast.
What was the weather like when you painted? Is the primer peeling too, or just the top coats?
Andy
"Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein
"Get off your dead #### and on your dying feet." Mom
Thanks Andy... Painting conditions were dry, 70-80's, and hte failure is at paint/wood interface. The siding was not completely sanded bare, and now I am wondering if the new paint system is pulling off the original paint. There is no liquid water in any of the blisters that I have popped.
You could be right about the new paint pulling the old off, but as I understand it, that usually happens when there's a severe temperature change.
Did any of the painting go on in full sun? (Right, you did say Seattle). Given the temps, you're probably right about the moisture drive. Still, it's odd that it would be one side only. Are you certain there are no significant moisture sources in that wall?
Jon Tobey, one of FHB's best painting authors, lives in Seattle. You might look him up for an expert opinion.Andy
"Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein
"Get off your dead #### and on your dying feet." Mom