foam application to 100year old house on gulf coast | Ask Mason Knowles - SPF Consultant | Spray Foam Technical Questions and Answers | SprayFoam Magazine Q&A Forums

Q&A Forums

foam application to 100year old house on gulf coast Post New Topic | Post Reply

Author	Comments
Posted: Nov 27, 2007 07:07 PM	foam application to 100year old house on gulf coast what application of foam to subflooring of 100 year house on humid gulf coast that is on bayou. house is on piers 2 to 3 feet off the ground. will this stop air infiltation that makes house cold and unable to keep warm during the winter. I am worried about condensation/mold issue and/or dry rot.
mason Posted: Nov 28, 2007 06:57 AM	Closed cell sprayfoam installed to the underside of the wood floor will seal very well. It is recognized by FEMA as a flood zone approved insulation because it can withstand standing water without losing its physical properties and seal against water intrusion. You should not have any problem with moisture so long as the wood is sufficiently dry before you spray. (18% or less moisture) My mom's house in Houston is over 60 years old and has had 2 lb sprayfoam installed to the underside of the wood floor for the last 35 years. Dry as a bone inside, no condensation, no moisture problems. In fact the foam stopped condensation problems in the closets while also preventing insects, rats and other varmits from getting inside the house
Posted: Nov 29, 2007 04:32 PM	mason, thanks for info. does there need to be plastic on the ground? is there a dry rot issue of the subflooring after CC foam application? what thickness should foam be applied? thanks!! any particular cc foam do you recommend. there is just now starting to have foam insulator after the hurricane but some are questionable and I want to make an educated decision before I commit to the expense/advantage. This is one of the only century old homes on the water that wasn't damaged and I would hate to have problems that I caused.
mason Posted: Nov 29, 2007 08:57 PM	I presume the crawl space is not sealed. If not then no plastic is required. The foam will protect the wood by itself. Any moisture that gets into the foam can come out of the foam at the same rate. Make sure the wood is dry before application. (18% moisture content or less) I would use a 2 to 2.5 lb density closed cell foam. 2-3 inches thick
philip mullins Posted: Dec 02, 2007 02:34 PM	jhl3, i know what you meen about questionable applicators. here in gulfport, we have seen several out of town applicators, as well as a couple of new contractors. i have encoutered competitors bids for closed cell in the 60 cents per board foot range. that is way to low.especially for crawling under a house. when someone bids real low like that, then goes under thier and sprays a thin coat, the home owner doesnt get the expected results and forms a low opinion of spf in general. when applied correctly, thier is no better product that you can use for your application. no more moisture, or drafts coming up thrue the floor. and go ahead and say goodbye to your rodent problem. you will feel the difference immediatly. the majority of my work lately has been crawl spaces and spraying the undersides of roof decks in existing homes, for severe weather durability, comfort, and energy savings. and, according to my customers, the results have been awsome. just be sure to check references before you hire. some of us 'newbies' are working hard to build a reputations and, quite frankly, care about our work a little more than some of the more established guys. make sure that you are getting the proper depth of foam. and that it is applied correctly. a guy can realy screw up a house doing it wrong. thier is always somebody cheaper! go for the best! magnoliafoam.com
mason Posted: Dec 03, 2007 06:47 AM	good advice troutkiller, always check references carefully
Posted: Dec 16, 2007 08:08 PM	mason thanks for your info. another question for cc on the century old house. is there any problem with cc foam contracting,cracking,brittleness during severe climate changes? will this change {ie.cracking,due to the stiffnes properties of cc} effect the air infiltration and stack effect that the cc foam is being applied to prevent. this question stems from my brothers foam contractor telling him to use oc foam for all applications
Posted: Dec 17, 2007 08:33 AM	mason thanks for info.another question to the cc foam . is there contraction, shrinking or brittleness associated with cc foam that would effect the air infiltration and stack effect that I am trying to stop during the winter. this was a question that was brought up by my brother, whose oc foam contractor in La. told him. May be because that was what he sprayed. please set the record straight. and to troutkiller, if you would return phone messages you may get the job!
mason Posted: Dec 17, 2007 03:25 PM	All foam plastic (including open cell foam) will shrink a little in colder climates and grow a little in warmer climates. However unless you are in temperatures that are consistently below zero, a nominal 2 lb density sprayfoam should maintain an acceptable dimensional stability and not pull away from the framing. Having said that, a few factors could affect the adhesion and dimensional stability of the foam during application. The substrate should be suffciently dry (wood 18% moisture content or less The substrate should be warm enough (per manufacturer's recommendations The foam should be installed correctly, not too thick (1.5 inches per lift or less, unless specifically recommended by the manufacturer.) Check the data sheet of the foam supplier. Look for response to humid aging. If it has more than 12% total volume change or more than 6% in a linear direction, the foam may shrink too much in cold climates.

Author

Comments

Posted: Nov 27, 2007 07:07 PM

foam application to 100year old house on gulf coast

what application of foam to subflooring of 100 year house on humid gulf coast that is on bayou. house is on piers 2 to 3 feet off the ground. will this stop air infiltation that makes house cold and unable to keep warm during the winter. I am worried about condensation/mold issue and/or dry rot.

mason

Posted: Nov 28, 2007 06:57 AM

Closed cell sprayfoam installed to the underside of the wood floor will seal very well. It is recognized by FEMA as a flood zone approved insulation because it can withstand standing water without losing its physical properties and seal against water intrusion.

You should not have any problem with moisture so long as the wood is sufficiently dry before you spray. (18% or less moisture)

My mom's house in Houston is over 60 years old and has had 2 lb sprayfoam installed to the underside of the wood floor for the last 35 years. Dry as a bone inside, no condensation, no moisture problems. In fact the foam stopped condensation problems in the closets while also preventing insects, rats and other varmits from getting inside the house

Posted: Nov 29, 2007 04:32 PM

mason, thanks for info. does there need to be plastic on the ground? is there a dry rot issue of the subflooring after CC foam application? what thickness should foam be applied? thanks!! any particular cc foam do you recommend. there is just now starting to have foam insulator after the hurricane but some are questionable and I want to make an educated decision before I commit to the expense/advantage. This is one of the only century old homes on the water that wasn't damaged and I would hate to have problems that I caused.

mason

Posted: Nov 29, 2007 08:57 PM

I presume the crawl space is not sealed. If not then no plastic is required. The foam will protect the wood by itself. Any moisture that gets into the foam can come out of the foam at the same rate. Make sure the wood is dry before application. (18% moisture content or less)
I would use a 2 to 2.5 lb density closed cell foam. 2-3 inches thick

philip mullins

Posted: Dec 02, 2007 02:34 PM

jhl3, i know what you meen about questionable applicators. here in gulfport, we have seen several out of town applicators, as well as a couple of new contractors. i have encoutered competitors bids for closed cell in the 60 cents per board foot range. that is way to low.especially for crawling under a house. when someone bids real low like that, then goes under thier and sprays a thin coat, the home owner doesnt get the expected results and forms a low opinion of spf in general.

when applied correctly, thier is no better product that you can use for your application. no more moisture, or drafts coming up thrue the floor. and go ahead and say goodbye to your rodent problem. you will feel the difference immediatly. the majority of my work lately has been crawl spaces and spraying the undersides of roof decks in existing homes, for severe weather durability, comfort, and energy savings. and, according to my customers, the results have been awsome.

just be sure to check references before you hire. some of us 'newbies' are working hard to build a reputations and, quite frankly, care about our work a little more than some of the more established guys. make sure that you are getting the proper depth of foam. and that it is applied correctly. a guy can realy screw up a house doing it wrong. thier is always somebody cheaper! go for the best!
magnoliafoam.com

mason

Posted: Dec 03, 2007 06:47 AM

good advice troutkiller, always check references carefully

Posted: Dec 16, 2007 08:08 PM

mason thanks for your info. another question for cc on the century old house. is there any problem with cc foam contracting,cracking,brittleness during severe climate changes? will this change {ie.cracking,due to the stiffnes properties of cc} effect the air infiltration and stack effect that the cc foam is being applied to prevent. this question stems from my brothers foam contractor telling him to use oc foam for all applications

Posted: Dec 17, 2007 08:33 AM

mason thanks for info.another question to the cc foam . is there contraction, shrinking or brittleness associated with cc foam that would effect the air infiltration and stack effect that I am trying to stop during the winter. this was a question that was brought up by my brother, whose oc foam contractor in La. told him. May be because that was what he sprayed. please set the record straight. and to troutkiller, if you would return phone messages you may get the job!

mason

Posted: Dec 17, 2007 03:25 PM

All foam plastic (including open cell foam) will shrink a little in colder climates and grow a little in warmer climates. However unless you are in temperatures that are consistently below zero, a nominal 2 lb density sprayfoam should maintain an acceptable dimensional stability and not pull away from the framing. Having said that, a few factors could affect the adhesion and dimensional stability of the foam during application.
The substrate should be suffciently dry (wood 18% moisture content or less
The substrate should be warm enough (per manufacturer's recommendations
The foam should be installed correctly, not too thick (1.5 inches per lift or less, unless specifically recommended by the manufacturer.)

Check the data sheet of the foam supplier. Look for response to humid aging. If it has more than 12% total volume change or more than 6% in a linear direction, the foam may shrink too much in cold climates.

You need to login to reply to this topic. Please click here to login.