Paint

Paint

Repair

Re-painting

Remove the affected paint coating and re-paint the surface. Surface should be cleaned before applying the paint. Surface preparation is critical for any painting application to obtain the effective functional performance of the system.

Construction Factors

Lack of application of waterproofing membrane around the floor trap can lead to moisture seepage creating a moisture pressure over the paint film. However, dense concrete itself is a good waterproofing material. But, water-tightness performance of the concrete is depending on the quality of mix and workmanship. Here, the concrete slab failed to achieve the required performance.

Design Factors

Lack of sufficient details of waterproofing around this pipe may lead to ineffective application of the waterproofing around the pipe.

Re-painting

Scrape off all loose existing paint films and wash the surface clean. This is necessary to remove dirt and grease which would otherwise cause failure. Repaint on a cleaned substrate with a new coat of paint. Good Industry Practices- Painting provides the instruction of painting process. Follow the details and instructions given in the Good Industry Practices- Painting for painting.

Use of Water-Repellents

In recent years there has been a new development on a new class of materials called silicones. They are usually used in the building field mainly in attempts to rectify penetration problems of rain into unit masonry. Some manufacturers also advocate the use of such materials to prevent the formation of efflorescence on masonry walls. When a brick or other types of units are treated with silicone, the surface usually becomes highly water-repellent.

Design Factors

The system is not effective to control the water seepage through the substrate. This lack of water-tightness of the wall allows water to seep through the wall.

Construction Factors

Poor surface preparation, such as presence of dirt and moisture may contribute to the formation of this defect. Further, poor construction quality of brick wall attributes the water seepage through external wall and through concrete floor. In masonry walls, mortar joints are more porous and hence more susceptible to water penetration.

Therefore, care should be taken when constructing such mortar joints.

Another possibility for such defect to occur is the incorrect application of paint system to the wall. Paint coat might be applied over the surface before the previous layer is able to dry out. Thus serious flaking takes place.

Re-paint

Burst the blister to remove the water trapped beneath. Scrape off any loose paint with a power washer and then recheck the area. Check for and repair leakage sources such as cracks, or other sources for water seepage. Paint the surface. Make sure the surface is dry and clean enough for new application of coating.

Refer Good Industry Practices-Painting.

Construction Factors

Failure from poor waterproofing details around the pipe penetrations allows water to get trapped under the paint coating. As more water gets trapped beneath the paint film, blisters start to form.

Design Factors

Insufficient design details on waterproofing around these pipe penetrations may render the contractor to do ad-hoc or improper waterproofing at these areas

Repair

Track the leakage source and seal up with grout. Remove blisters by scraping or sanding. Test the adhesion of the paint on the surrounding areas by applying a length of tape on the surface and removing it with a quick motion. If there is a large scale lack of adhesion, the entire surface should be scraped and sanded. Prime surface with a quality latex or oil primer. Repaint the dry and clean surface and trim.

Construction Factors

There are a couple of possible reasons:

• Failure of proper application of waterproofing membrane allows water to flow to the concrete slab and through it. Water gets trapped underneath the paint film and as more of such water collects at the particular spot, blisters grow.
• Incorrect painting method was used. Painting over wet layers may cause moisture to get trapped between laps. As more of such moisture is trapped and collected at a spot, blisters form.