EPDM membrane cannot be directly applied or be in contact with any product containing coal tar pitch, creosote or penta-based materials. Contaminants such as petroleum grease, acid, solvents, vegetable or mineral oils and animal oils or fats will soften and degrade the membrane.
Asphalt based roof cements or mastics cannot be used as a patch. Direct steam venting can also cause degradation and should be avoided. Standing water or wet leaves have no adverse effect on the membrane. In fact, EPDM has been used for pond liners for years. Nevertheless, ponding should not be allowed on any flat roof.
In other words, water should not remain on a roof 48 hours after precipitation. Manufacturers of EPDM recommend a positive drainage system (1/4″ per foot). Over time ponding can exceed structural design weight allowances. Also freezing over seams can apply stress that may lead to seam failure.
An article by John Cranor for Ashi Reporter discusses EPDM roofing. Some commercial roofs like ethylene propylene diene monomer (EPDM) can be used on both low and steep roofs, as well as commercial and residential applications. However, they’re more common in the former because the roofing profile of most shops and stores is flat. Since it’s designed as a standalone system, experts suggest against laying EPDM on asphalt or any surface covered in oils.
EPDM suffers from chemical compatibility; it may resist moisture, but it will sustain damage from oils and hydrocarbons (case in point: fuel). This type of roofing cannot be used in environments where it’s often in contact with these chemicals. The adhesive used for bonding EPDM may activate the dead asphalt and result in no bond with the surface; however, you can use a wood or concrete substrate in installing this type of Katy, TX roofing.
The same can be said for patching up holes and other blemishes in EPDM roofing surfaces. Roofing contractors such as Summit Roofing & Restoration commonly use a special glue designed for EPDM roofs where the solution is as simple as covering the hole with an EPDM patch. Make sure the patch is big enough to cover the damage (at least three inches outward) and is properly bonded.
With the right installation and repair, you can bring out the full potential of EPDM for flat roofs. Katy roofing technology has evolved to the point that people have access to the right materials and skills.