Inside Concrete Wall Blistering

The air collects in spots under this airtight surface seal and creates blisters.

Inside concrete wall blistering.

This condition eventually leads to peeling. Heat blistering caused by painting in direct sunlight on a surface that is too warm. It also saturates insulation reducing energy efficiency. It begins when either bleed water or bubbles of entrapped air move through the concrete and are unable to escape the surface.

Exposure of latex paint film to dew high humidity moisture or rain shortly after paint has dried especially if there was inadequate surface preparation and or poor ventilation in areas such as. Paint blisters or bubbles occur when the paint film lifts from the underlying surface. Soaking the wall before using strong chemicals prevents the masonry from absorbing too much which can deteriorate the ingredients inside the concrete and lead to wall failure. Blistering occurs when air gets trapped in the concrete and can t break out of the seal that may be created during finishing operations or caused by a rapidly setting surface.

Concrete bister blisters are hollow low profile bumps on the concrete surface typically from the size of a dime up to 1 inch 25 mm but occasionally even 2 or 3 inches 50 75 mm in diameter. Why does concrete blistering happen. Usually the surface was sealed too early during finishing resulting in the hidden voids of air and bleed water underneath the mortar skin. It can be corrected but the underlying cause of the problem must be addressed or it will recur.

Moisture blistering can be caused by the migration of water through an interior wall to the exterior thus pushing the paint off of the surface. Wait for the adhesive to dry to the point where it loses it s wet look but remains sticky to the touch. Brush a layer of concrete bonding adhesive over the scraped area. Efflorescence is normal for new portland cement applications but the presence of efflorescence in older concrete usually belies an underlying moisture problem.

The adhesive will aid in binding the new plaster patch to the old plaster surface. Paint applied to concrete experiencing efflorescence will bubble and blister. A dense troweled skin of mortar about 1 8 in. 3 mm thick covers an underlying void that moves around under the surface during troweling.

Application of oil based or alkyd paint over a damp or wet surface. When broken small pockets of white powder may ooze from the blisters.