FAQ: Expansion Joints and Sealants

Do EIFS require expansion joints?

Expansion joints in EIFS are required at the following locations:

where they exist in the substrate or supporting construction
where the EIFS adjoins dissimilar construction or materials
at changes in building height or other areas of anticipated building movement
at floor lines in multi-level wood frame construction
where prefabricated panels abut one another
where the substrate changes

How wide should expansion joints be when installed with the EIFS?

This issue is the responsibility of the design professional.

Can a "V" groove reveal be considered a joint?

A "V" grove reveal is aesthetic and cannot be considered a joint since a true joint is a "built-in" break in the system where movement of the wall is anticipated which can result in cracking. Reveals in EIFS are strictly aesthetic and are used to provide convenient stopping points for finish application in large wall areas. If movement relief is necessary, a full expansion joint with sealant is necessary. The term “control joint” is not used in the EIFS industry.

Is it necessary to install sealants?

Yes. Sealants are always required around windows, doors, all service openings, and at the juncture of dissimilar materials. This is true for every type of wall cladding. Sealants are not a part of the EIFS system; however, their use in conjunction with the system is a necessity. Moisture damage caused by failure to properly apply sealants at those points just named is not covered by manufacturers' warranties.

Are there alternatives to applying sealants around my windows?

No. The sealants around the perimeter of your windows, and the sealant around doors, dryer vents, house bibs, and every other service opening serve a critical function; they help keep your home tight and help in keeping water out of your walls. If the sealant is properly installed as specified by the sealant manufacturer, these can give you many years of protection.

Why must a closed cell backer rod be used with EIFS?

The use of closed cell backer rod (instead of open cell) behind sealants is recommended to prevent premature failure of the sealant joint. Open cell backer rod will absorb and hold water that could affect the sealant/EIFS bond line.