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Posted: Mar 22, 2008 11:37 PM	electrical nightmare Just picked up a new constrution job that will be insulated with the poly. spray foam instead of glass. Whats the best way to rough in for in walls and in ceilings? Also I am guessing open back LV brackets are out? Anything else I should do to deal with this? Basically, what can we do to protect our speakers and keypads from the foam? Stick fiberglass behind the keypads and speakers, use back boxes, framing,...what do you recommend? THANKS!
mason Posted: Mar 23, 2008 10:59 AM	The sprayfoam as you suggested is installed as a liquid and expands to fill in cracks and crevices in the spaces. So, anything that should not have foam on it (or in it), should masked off. Tape and plastic work well for most items. Any "hot" surfaces (200 degrees or more) should be insulated from the foam since the foam will char at those temperatures and above. Overspray can be a problem so mask off any items that may get foam on it in the room and in other rooms where the foam may drift. Ask your contractor how they plan to protect the specific items you mentioned.
Posted: Mar 23, 2008 02:09 PM	Thanks for the info still curious about roughing in where i need extra wire length that i can't leave in wall cavity due to foam. Will foam melt or damage any of my wires? How will the foam effect my speakers, sound quality? can i still use open back boxes? Thanks again
mason Posted: Mar 24, 2008 07:35 AM	There is exothermic heat released by the foam when it sets up. (typically around 200 degrees F although it can go higer with thicker applications. The thicker the application (speaking of closed cell foam) the greater the heat released. In order to reduce the heat build up, the contractor should spray 1-2 inch thick lifts then let it set for around 10 minutes before building up greater thickness. Find out what heat resistance the wiring has, regular wiring for 110 outlets should withstand the heat with no problems, but smaller wiring for security systems, sound systems, etc may not have the same heat resistance.
mason Posted: Mar 24, 2008 07:40 AM	I am not sure how the foam will affect the speakers sound quality. Any experience out there?
quentin Posted: Mar 25, 2008 11:23 AM	If I have the make and model of the speakers being used I may be able to help. An open back installation may be using a port system to boost low end sound performance or to increase the size of the box so it is hard to tell without the specs. Let me know and I can likely be of assistance in that end. I used to own a home and car audio business so have some knowledge there but it will take some info and checking.
Posted: Apr 02, 2008 12:09 AM	Appreciate the offer job went well another guy with foam experience helped out. I will be back next time would like your input next time Thanks again

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Posted: Mar 22, 2008 11:37 PM

electrical nightmare

Just picked up a new constrution job that will be insulated with the poly. spray foam instead of glass. Whats the best way to rough in for in walls and in ceilings? Also I am guessing open back LV brackets are out? Anything else I should do to deal with this? Basically, what can we do to protect our speakers and keypads from the foam?
Stick fiberglass behind the keypads and speakers, use back boxes, framing,...what do you recommend? THANKS!

mason

Posted: Mar 23, 2008 10:59 AM

The sprayfoam as you suggested is installed as a liquid and expands to fill in cracks and crevices in the spaces. So, anything that should not have foam on it (or in it), should masked off. Tape and plastic work well for most items. Any "hot" surfaces (200 degrees or more) should be insulated from the foam since the foam will char at those temperatures and above.

Overspray can be a problem so mask off any items that may get foam on it in the room and in other rooms where the foam may drift.

Ask your contractor how they plan to protect the specific items you mentioned.

Posted: Mar 23, 2008 02:09 PM

Thanks for the info still curious about roughing in where i need extra wire length that i can't leave in wall cavity due to foam. Will foam melt or damage any of my wires? How will the foam effect my speakers, sound quality? can i still use open back boxes? Thanks again

mason

Posted: Mar 24, 2008 07:35 AM

There is exothermic heat released by the foam when it sets up. (typically around 200 degrees F although it can go higer with thicker applications. The thicker the application (speaking of closed cell foam) the greater the heat released. In order to reduce the heat build up, the contractor should spray 1-2 inch thick lifts then let it set for around 10 minutes before building up greater thickness.

Find out what heat resistance the wiring has, regular wiring for 110 outlets should withstand the heat with no problems, but smaller wiring for security systems, sound systems, etc may not have the same heat resistance.

mason

Posted: Mar 24, 2008 07:40 AM

I am not sure how the foam will affect the speakers sound quality. Any experience out there?

quentin

Posted: Mar 25, 2008 11:23 AM

If I have the make and model of the speakers being used I may be able to help. An open back installation may be using a port system to boost low end sound performance or to increase the size of the box so it is hard to tell without the specs.

Let me know and I can likely be of assistance in that end. I used to own a home and car audio business so have some knowledge there but it will take some info and checking.

Posted: Apr 02, 2008 12:09 AM

Appreciate the offer job went well another guy with foam experience helped out. I will be back next time would like your input next time Thanks again

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