applying roof coating

[bnrboy775]

I have been thinking about coating my roof with a white elastomeric coating to reflect the heat and help my cooling bills as the roof I have now is a metal roof that is brown in color. Im sure that it just sucks up the heat. I already bought black jack roof coating from lowes. It says on the bucket to apply in the morning. Only problem is that I work mornings and wont be able to apply it. Is there a problem with applying it later in the day. Obviously I probably wont be able to get it all covered in one day. But what about the drying and stuff? The nighttime temps are staying in the upper 60's so its abovethe reccomended temp. Also are there any tips you guys have for walking on the roof? For a little more info the roof is metal laid over shingles. Looks like maybe two layers on them. Would coating this really help a lot?

[Greg]

The reason for doing it in the morning is because it is cooler and the sun is not as strong. Applying it when it is hot with a direct sun the drying time is greatly reduced. If you wait until a cool or overcast day you should be OK.

Greg

[slk_ms]

I was wondering the same thing as well. I will be doing this soon and was also wanting to know how long it takes to roll a 16 x 80? I will be attempting this myself so any suggestions would be greatly appreciated.

[Greg]

It took me a few hours to do ours, I spent a few hours the day before "preping" a few rust spots & cleaning.

Greg

[flcruising]

I'm not even sure I would use elastomeric for a metal roof. We use it here all the time for stucco or cmu because it is so thick and can fill the pores better than regular paint. But with a smooth finish like metal, I would suggest you just use exterior paint. It is ALOT cheaper and goes ALOT further. I certainly suggest a primer be used, but since you aren't going for it's weatherproofing ability, you will definitely save labor and money by using paint. I understand that elastomeric has better elongation properties as well, but once you paint your roof white, the thermal expansion won't be nearly as drastic because of the reduced heat absorption.

That's my $.02

[DaveyB]

I agree with Aaron about going the paint route instead. Since the roof is a "retread" (metal roof over shingles) you don't have to worry much about leak-proofing, it's the color change you're more interested in. Additionally, paint could be sprayed on, making the whole job much faster and less worry about it drying out before you are done. Obviously, the cooler the roof when painted, the better the bond will be.

As regards moving around on the roof, most areas in the US require the roof to support a foot or so of snow, so it will support up to around a 180lb man - if you are over that, consider using walk boards as well. Better safe than sorry!!

Hope that helps!

DaveyB