Roof Ice Damming

[DRH]

Originally Posted by Blue Thunder

Just as a clarification and not really adding to the good advice above, the "bituthene" being referrred to above is lovingly referred to by contractors as "B*tchaThane" because it is a b*tch to work with. It is an extremely thick and sticky, on one side, rolled membrane that nearly all roofing contractors use these days when roofing. W.R. Grace was one of the first to come out with it in the 80's and it is on the shelf at Home Depot and Lowes as "Ice and Water Shield". It comes in rolls that are 3 feet wide similar to felt paper.

In my own personal case, I had my roof done in the mid 80's and we used this product. The standard back then was just to do one layer/run 3 feet up from the eaves. Now a days I see many roof jobs where this product is used the whole way up the roof and I opted to do this myself when I had my roof done again this past summer.

BT

Our roof is unusual with compound angles and two long valleys. We used to get leaks whenever we had heavy, wind-driven rain. Several years ago we had the roof stripped and covered 100% with bituthene (Grace Ice & Water Shield) prior to re-shingling. With the roof completely protected by the bituthene under the new shingles, we haven't had a single leak.

BTW, our contractor referred to it just as BT stated!