Roofing roof coatings, shingle roof, hydrostop

Roofing roof coatings, shingle roof, hydrostop

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Expert: Mark Sundberg — 7/1/2008

Question

QUESTION: Is white lava better than hydrostop and can white lava be applied over asphaut shingles 20yrs old-thanks,keith

ANSWER: Aloha Keith,

Better in which regard? For temporarily stopping leaks or long term use or for keeping the inside cool and, of course, as compared to what price?

Even more basic is which White Lava and which Hydrostop product do you want to compare.

Both appear to have a number of certification but unless I know which product you are considering and for what purpose and which particular criteria you consider most important, it’s quite impossible to give you any meaningful answer.

I will say, since White Lava appears to be a local Hawaiian product, I’d be in favor of it for the aspect alone. But whether which one performs better for which purpose, I can’t say.

QUESTION: We have a 20year old asphault shingle roof in 12×12 pitch and it gets so hot inside. We have two 10 year old solar fans which no longer work as well. We live in Hawaii and heard about White Lava roof coating and hydrostop roof coating that would cool our house. I was wondering which one would apply to the shingles better and reduce the heat more. Thanks again, keith

Answer

Aloha Keith,

The best answer I can give for this is to refer you to the Cool Roof Rating Council web page.

and to the following items:

0768-0001 Hydro-Stop Inc.

Perry Smith (843-745-9600) Hydro-Stop, Inc.

Premium Coat White Finish Coat 2003-015 Other — Fluid Applied Roofing 0.79** pending 0.90**** pending Low/Steep

0940-0001 White Lava Products

Rick LeGrand (808-487-3043) White Lava Products Tropical Roofshield Field-Applied Coating

0.83** pending 0.94**** pending Low/Steep

** This is the Solar Reflectance rating, it is a measure out of 100 of how much of the solar energy will be reflected. Obviously, the higher the number, the less heat will get into your building as it will be reflected away.

**** This is the Emissivity rating, it is a measure out of 100 of how much heat energy in the coating will be emitted into space. Again, the higher the amount, the better.

As you can see, the White Lava product has better ratings in both categories, reflectivity and emissivity. Based on that, it would be the one I’d select. Neither has a long term application rating (which is what the ‘pending’ refers to, meaning they haven’t had test data for long exposures approved. That doesn’t mean they are not any good over the long haul, just they haven’t been tested and approved yet.

The difference in performance is not huge, but it is significant. 79 vs 84 gives better than 6dge to the White Lava in reflectivity and the other, 90 vs 94 gives almost a 4.5

dvantage in emissivity.

However, I have no ideas about what sort of application issues there may be nor what the difference in cost would be. Make sure when you compare the two that you compare the cost of the product when it arrives at your house, not what’s in a catalog someplace. I’d also recommend you give consideration as to whether a product has a local representative for it. Obviously, White Lava does here on Oahu but I wouldn’t know about where you might be.

I have used similar products on a house here that had a very low slope roof with no insulation that was quite hot during the afternoon. It was not possible to hold your hand against the wood decking on the inside it was so hot. That heat was radiating into the room and to us making us hot, making the furniture hot, making everything hot. After I had applied the reflective roofing, it made about a 5 degree difference in the air temps inside and it was substantially cooler feeling because there wasn’t that big hot plate up above us. I could hold my palm against the roof decking and I’d guess, while it was still quite warm, it was at least 25F cooler to the touch. It made a huge difference in comfort.

Advertisement

Expert: Mark Sundberg — 7/1/2008

Question

QUESTION: Is white lava better than hydrostop and can white lava be applied over asphaut shingles 20yrs old-thanks,keith

ANSWER: Aloha Keith,

Better in which regard? For temporarily stopping leaks or long term use or for keeping the inside cool and, of course, as compared to what price?

Even more basic is which White Lava and which Hydrostop product do you want to compare.

Both appear to have a number of certification but unless I know which product you are considering and for what purpose and which particular criteria you consider most important, it’s quite impossible to give you any meaningful answer.

I will say, since White Lava appears to be a local Hawaiian product, I’d be in favor of it for the aspect alone. But whether which one performs better for which purpose, I can’t say.

Roofing roof coatings, shingle roof, hydrostop

QUESTION: We have a 20year old asphault shingle roof in 12×12 pitch and it gets so hot inside. We have two 10 year old solar fans which no longer work as well. We live in Hawaii and heard about White Lava roof coating and hydrostop roof coating that would cool our house. I was wondering which one would apply to the shingles better and reduce the heat more. Thanks again, keith

Answer

Aloha Keith,

The best answer I can give for this is to refer you to the Cool Roof Rating Council web page.

and to the following items:

0768-0001 Hydro-Stop Inc.

Perry Smith (843-745-9600) Hydro-Stop, Inc.

Premium Coat White Finish Coat 2003-015 Other — Fluid Applied Roofing 0.79** pending 0.90**** pending Low/Steep

0940-0001 White Lava Products

Rick LeGrand (808-487-3043) White Lava Products Tropical Roofshield Field-Applied Coating

0.83** pending 0.94**** pending Low/Steep

** This is the Solar Reflectance rating, it is a measure out of 100 of how much of the solar energy will be reflected. Obviously, the higher the number, the less heat will get into your building as it will be reflected away.

**** This is the Emissivity rating, it is a measure out of 100 of how much heat energy in the coating will be emitted into space. Again, the higher the amount, the better.

As you can see, the White Lava product has better ratings in both categories, reflectivity and emissivity. Based on that, it would be the one I’d select. Neither has a long term application rating (which is what the ‘pending’ refers to, meaning they haven’t had test data for long exposures approved. That doesn’t mean they are not any good over the long haul, just they haven’t been tested and approved yet.

The difference in performance is not huge, but it is significant. 79 vs 84 gives better than 6dge to the White Lava in reflectivity and the other, 90 vs 94 gives almost a 4.5

dvantage in emissivity.

However, I have no ideas about what sort of application issues there may be nor what the difference in cost would be. Make sure when you compare the two that you compare the cost of the product when it arrives at your house, not what’s in a catalog someplace. I’d also recommend you give consideration as to whether a product has a local representative for it. Obviously, White Lava does here on Oahu but I wouldn’t know about where you might be.

I have used similar products on a house here that had a very low slope roof with no insulation that was quite hot during the afternoon. It was not possible to hold your hand against the wood decking on the inside it was so hot. That heat was radiating into the room and to us making us hot, making the furniture hot, making everything hot. After I had applied the reflective roofing, it made about a 5 degree difference in the air temps inside and it was substantially cooler feeling because there wasn’t that big hot plate up above us. I could hold my palm against the roof decking and I’d guess, while it was still quite warm, it was at least 25F cooler to the touch. It made a huge difference in comfort.


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