Common Painting Problems
If you have blistering paint on your home, it is important to determine what has caused the blister.
Heat blisters are caused when paint is applied in direct sunlight or in hot weather. It is more common on dark colours, as dark colours absorb heat and light, getting hotter than lighter colours which reflect them.
Moisture blisters are caused when the sun heats the exterior wall, which draws the interior moisture through walls, trapping it beneath the exterior coat of paint. Moisture blisters indicate that the wood beneath the paint is wet, and that wood rot is not far off.
Knot blisters are caused by painting over wood knots without properly sealing them with shellac. The sun heats the knot and draws its sap to the surface, trapping it beneath the paint.
The best way to distinguish between the three types of blisters is to pop them. If a blister reveals bare wood, and no knots or sap residue are present, moisture is usually the problem. Beneath a heat blister, the previous coat of paint is visible. When a blister is properly diagnosed, the correct repair and preparation is clear.
If the appropriate preparation is not done, the blister will reappear beneath a fresh coat of paint. All blisters must be properly analyzed, and properly prepared, in order to avoid costly repairs in the future.
Heat blisters must be sanded, primed if a bare surface is exposed, and painted in cooler temperatures. We will not paint in direct sunlight, as this is the primary cause of heat blisters.
We will sand knot blisters to ensure that all sap is removed. Shellac and primer will be applied so the blister will not reappear.
Many times moisture blisters are brought to light by a new paint coat because the old paint coat was cracked and worn, allowing moisture to escape. Possible solutions to moisture blisters are to cut back excessive plant and shrub growth from your home to reduce moisture, identify and repair faulty roofs, caves, or windows, or install vents on exterior walls of soffits. Once the source of the moisture has been removed, moisture blisters will be scraped, sanded, and permitted to dry before they are primed and painted.
If the root cause of the blister is not solved, we will be unable to guarantee that it will not reappear. If, however, the cause of the blister is isolated, and we are certain the condition is cured, we will guarantee these repairs for three years.