Modifed Bitumen roofing vs standing water
I have just had a 3500 SF roof redone by a roofing contractor using a Modified Bitumen system. There are a couple of spots that have standing water. The roofing contractor says it is to be expected and is allowable. My client is unhappy about it. Should I be concerned about this? Is there an allowable minimum for standing water or should there be none at all?
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Most low slope roofs have some ponding. If it doesn't evaporate in 24 hours during warm weather, it is an issue.
standing water on roof
Is this an older building that indeed has a FLAT roof? Or is it what is often called a flat roof but really has a minimun pitch. Say 1/4" per foot.
If the overall pitchis 1/4"
If the overall pitchis 1/4" to the foot then it is right. Material thicknbess and laps will cause minor standing water possibilities behind a lap.
But if the seam itself is under water and/or the water does not evaporate in a day, there is a problem. That water will fiond a way to leak into the seam or to deteriorate the material itself