FAQ's: New Construction

Q. What is construction window cleaning?

This type of window cleaning requires the window cleaner to be specifically trained to remove several types of construction debris from the glass without scratching.

Q. What are the most common tools used to remove construction debris from glass?

Metal scrapers and razor blades have been the standard for construction window cleaning and remain the proven method to safely remove construction debris from glass without scratching.

Q. What chemicals are used to remove plaster, concrete and mortar from glass?

Products with phosphoric acid are commonly used. The acid dissolves the cement in the debris and makes it much easier to remove. Beware of any side effects on surrounding stucco and IG seals.

Q. What is used or recommended to wet the window in construction window cleaning?

High quality window brushes are used for their ability to spread adequate water without scratching the glass. They help prevent sand from getting trapped between the brush and the glass. Strip washers are also commonly used, but hold less water and carry a higher risk of trapping construction debris, which can scratch glass more easily.

Q. Can steel wool be used to clean glass in a construction environment, without scratching the glass?

Yes. Steel wool is sometimes used to remove construction debris from glass, but carries a higher risk of scratching glass. If construction debris gets trapped between the steel wool and glass, scratching could result. Also, if steel wool is to be used, use only new steel wool. If rust is present in old steel wool, scratched glass will result.

Heat Treated Glass


Q. What is heat treated glass?

There are two main types of heat treated glass, fully tempered and heat strengthened.

Q. What is fully tempered glass?

Usually just called tempered glass, fully tempered glass is a safety glass used in many applications where the possibility of human contact is high. This glass is 4-5 times stronger than non-tempered glass and breaks into very small pieces when fractured.

Q. What is heat strengthened glass?

Heat strengthened glass is twice as strong as non-tempered glass. Fracture characteristics of heat strengthened glass vary widely from much like annealed glass to similar to fully tempered glass. For this reason, heat strengthened glass does not qualify as a safety glass.

Q. What is safety glass?

Fully tempered glass and laminated glass are classified as safety glass.

Q. What is laminated glass?

Laminated glass consists of two or more panes of glass with a tough plastic interlayer, bonded together under heat and pressure. Laminated glass is also used as an effective sound control product. Laminated glass is commonly used in airports, sound studios, schools and in houses near freeways to keep away unwanted noise from airplanes, heavy machinery and traffic.

Q. Where is safety glass usually located in a house or building?

Anywhere glass is more prone to human contact such as doors, windows close to the floor, stair landings and tub/shower enclosures. Check your local building code for details or more specific locations.

Q. How is tempered glass made?

Tempered glass must first be cut to the finished size, since it cannot be cut or modified after it is tempered. Then the edges are belt seamed or sanded to remove any sharp edges. Next it is washed to remove all fabricating debris. Finally, it is heated to almost 1200°F and then quick cooled, which produces the temper.

Q. How do you know if glass in a window is tempered?

All tempered glass windows must have a permanent tempering stamp applied to each piece of glass to signify it is tempered.

Q. Where is the tempering stamp located on the glass?

Tempering stamps are located in the corner of each and every piece of tempered glass.

Q. Is there a standard for washing glass before tempering?

No. But, it is highly advised that all glass be washed prior to tempering to remove all fabricating debris.