# can EPDM be applied directly on top of Ice and Water?



## Gloucester (Jul 4, 2012)

We are having a low pitched hip roof repaired (appx 20x20 - was rubber over tin). After taking the tin up the tongue and grove (T&G) planks are in good shape. The roofer is suggesting we keep the T&G planks, install ice and water (I&W) shield over all the T&G, and then install EPDM over the I&W. 

I am reading several comments that the EPDM is not compatable with I&W and should not be applied over the I&W - is this accurate? Also, the T&G roof is in good condition however there are small gaps, nail heads etc - should the I&W be applied directly over the T&G? Seems like a bad idea. 

The roofer was thinking he would save us $ by not taking up the T&G and installing a specialized plywood made specifically to apply the EPDM to directly to but this seems like a short term saving for a long term problem. 

comments and ideas welcome. I live in the north east near the ocean so snow, ice and wind are factors


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## gordieax (May 29, 2012)

I'm not an expert on this but based on my experience and research epdm needs to be installed over a substrate such as iso board, plywood or possibly osb. Also epdm should be fully adhered as in glued/cemented down. You cannot fully adhere epdm directly over the ice and water shield. It won't adhere properly without an appropriate substrate.


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## dougger222 (Feb 25, 2011)

Ice and water directly under EDPM is not a good idea as a matter of fact never heard of anybody doing that. 

The problem like G mentioned is there's really no way to adhear the rubber to the ice and water and the top side of the ice and water may stick to the bottom side of the rubber making it next to impossible to tear off both the rubber and ice and water shield down the road.

You gotta run an iso or fiberboard. OSB or plywood under the EDPM is not recomended as the glues in the decking will counteract with the glue for the rubber and cause issues.

Not an EDPM expert but done a few and did a seminar a few months back on the product. 

You need to talk with your "roofer" about the ice and water shield. A 20x20 area won't add too much to the project with iso or fiberboard.

Never tore off rubber on icd and water or osb/plywood but have torn off torch down to osb/plywood and it's horrible.


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## Maintenance 6 (Feb 26, 2008)

Ice and water is an asphalt based product. The oils from the ashalt will have a negative effect on the EPDM.


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## tinner666 (Mar 14, 2005)

No. Unless you're planning on redoing everything again in about 6 months time. Or less.


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## Chris Brink (Jul 5, 2012)

*EPDM over I&W*

Agree this sounds sketchy, particulary because the big issue is which adhesive will be used with the EPDM, and different adhesives do different things to different materials, there is a lot of variability in how compatible these products can be.

Using I&W and EPDM together is a bit redundant anyway, as each would be creating a continuous plane of water tightness.


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