There is open cell and closed cells foams. Open cell structure is tight enough to provide an excellent thermal and air barrier but open enough to allow vapor drive and moisture to penetrate. Closed cell structure is completely closed completely shutting off air, vapor and moisture penetration as well as providing the best thermal performance attaining R-7 per inch. Open cell is typically a 1/2 pound in density which is 1/2 pound per cubic foot cured and provides an R-3.5 per inch. Closed cell typically comes in 1.7, 2.0 and 2.7 pound density's.
Back to TopOpen cell is much lighter and softer being only a 1/2 pound per cubic foot. The two pound in much harder and tougher. The open cell gives you two barriers a thermal and a air barrier. The closed cell gives you four barriers, a thermal, air, moisture and vapor barrier. (Note fiberglass only gives you a thermal barrier) The open cell 1/2 pound expands 130 to 1, the two pound closed cell foam expands 30 to 1, and the 2.7 pound roof foam expands approximately 16 to 1. Open cell expands so much in a typical wall system it is typically full filled and cut off. The two pound you can control within reason. The R-value of the 1/2 pound is 3.5 per inch the two pound is approximately an R-7.0 per inch. An excellent example from SprayFoam.com (3.6 MB)
Back to TopThe open cell is an excellent wall foam and cathedral ceiling foam. Many like the open cell in cathedral ceilings because if the roof leaks it will leak through the foam and you have time to fix the roof before it rots. The closed cell is used as a residential wall foam, residential box sills, commercial stud wall foam, commercial cavity wall foam, below grade foundation damp-proofing and insulation, under floor insulation where hydronic heating is used and concrete is poured over the top, deck foam where pre-cast is place and insulated underneath, deck foam where it is sprayed between pre-cast and the concrete deck. These are only some of the main construction applications.
Back to TopSpray foam hits a point of diminishing return. Unlike fiberglass, because spray foam is a air barrier as well as a thermal barrier its performance levels can not be measured in R-value alone. With simply 1" of spray foam you will gain over 70% of your insulating value, 2" will give you 84% and 3" 90%. At 3" you will hit a point of diminishing return. R-Value Diminishing Return Spray Foam vs Fiberglass
Back to TopYes it does, the question is how much. The Energy department conducted tests on fiberglass and it showed it can lose as much as 28%. With spray foam it has an initial rating and a aged rating which drops approximately 5%. The big difference is once spray foam ages out it will not lose any more insulating value. (Read articles below) Oak Ridge Labs Results
Back to TopSpray foam will burn for the first 48 hours during the off gassing or curing period. Once it is cured it self extinguishes. The problem is it is a plastic and it will melt and if spray foam is consumed in a burning fire it gives off toxic fumes this is the reason for the required 15 minute burn barrier.
Back to TopAny occupied space with a couple of exceptions. Box sills or rim joist around a residence. Any totally enclosed crawl space and architectural buildings. (Verify with inspection departments. Typical burn barriers are 1/2 drywall or intumisent paint.
Back to TopThis is the jewel in almost doubling your energy efficiency in building envelopes. This is the big difference between fiberglass and spray foam. Fiberglass only works with thermal loss, spray foam works with thermal, air, moisture and vapor transmission. This is were testing has shown in Wisconsin you will save 40% on your heating bill. Air Barrier Article Energy Report - See page 21
Back to TopIt has excellent adhesion characteristics it will adhere to wood, metal, glass densglass just about any thing. It will not adhere to a wet surface, oily surface or plastic vapor barrier with vapor barrier it will curl. You can remove it with a wire wheel or a 3000 psi hot water pressure washer with a turbo tip. Urethane spray foam is the material that is used on the Space shuttle external fuel tanks they have trouble with the adhesion at 14000 mph.
Back to TopIf it is spray on construction equipment or building the over spray will eradicate naturally by the suns UV rays. If it needs to come off right away a 3000 psi hot water pressure water with a turbo tip will remove it. A wire wheel on a grinder will take it off. If it gets on cars a razor scraper will remove it off the windows. A experienced detail shop can remove over spray from clear coat cars. It generally cost around $125.00.
Back to TopCaviseal is used in cavity wall system where a air barrier and insulation is needed. Typical wall system use a spray on air barrier with 2" ridge insulation in front of it. Caviseal is spray urethane which provides both in one system. The advantage it is totally adhered to the substrate and is seamless and because of this on air can get behind the ridge insulation improving efficiency as much as 40%. It is by far the best system on the market.
Back to TopYes Spray urethane does vary, a nominal 2" spray foam job will vary from 2 1/2" to 1 5/8" however 2" of board stock is a R-5 per inch where as Caviseal is an R-7 per inch, so even if it only hits 1 1/2" you have the same R-value as board stock. Plus remember it is seamless and totally adhered giving you the highest performance.
Back to TopMason contractors need to have all the flashings installed and any lintels which need to be sprayed over. If spraying on densglass all the anchors need to be installed. Weather is a big concern. It has to be above 40 degrees when spraying Caviseal, fortunately masonry veneer has to be as well so most of the time we are installing in enclosures. Wind is another big factor, the wind needs to be 15 mph or less and headed in the right direction carry the over spray away from cars and existing buildings.
Back to TopCaviseal will burn over and change color as well as lose a 1/16 of an inch in the first month. After it burns over the degradation action slows and you will lose about an 1/8" in four months. However we want it to burn over some because it creates a hardened shell on the face increasing its permeability and moisture penetration characteristics.
Back to TopYes, Caviseal provides the air barrier and insulation barrier in one. Typical air barriers cost around $2.50 a square foot and the ridge insulation is about a dollar for installation and materials. Caviseal is about $2.50 a square foot so you should save a dollar a square foot for the system! Best of all is performance is significantly greater because its seamless and totally adhered to the substrate.
Back to TopUrethane has been used on roofs for years this is why it is an excellent damproofing. Hydrostatic pressure resistant tests confirm it. Most membranes are only 35 mils thick Thermaseal is at minimum a 1 1/2" thick. The best part however is the insulation performance. Builders have fought trying to anchor ridge insulation to foundation walls. The problem is you cannot nail into the foundation because it ruins the damproofing. Some excavators have had an extra labor hold insulation in place while they backfill. With Thermaseal it is totally adhered to the foundation wall system and is seamless.
Back to TopThe State of Wisconsin requires damproofing where the water table is not above the foundation line. Waterproofing is used where the water table comes above the foundation line. Thermaseal is warranted as a damproofing but performs as a waterproofing. Many suppliers of waterproofing membranes are only warranted as a damproofing but are called waterproofing. With Thermaseal you can add a coating on the outside to make it a true waterproofing and gain a waterproofing warrantee. This is the system that is used on municipal water tanks that are above ground.
Back to TopUV rays breakdown urethane so any foam that is above grade must be coated with a UV protectant paint.
Back to TopNo, with closed cell foam we pour concrete over it and then drive cars over it. With below grade foam there is very little pressure on a vertical wall. As far as soil Thermaseal is plastic and will last the life of the building. You can take the harshest of chemicals and it will not touch it including acid. You can melt it and grind on it other than that very little will touch it.
Back to TopBoth are excellent wall foams both give you thermal and air barriers even though the 2 pound gives you added moisture and vapor barriers. It becomes mute because the State of Wisconsin still requires a separate vapor barrier. The question becomes is what size thickness of wall do you have a 2 x 6 or 2 x 4 wall. A 2 x 6 wall full filled with 1/2 pound will cost the same as 2 1/2" of closed cell, the R-value for 5 1/2" of 1/2 pound would be around 19 where it would be around 17 for 2 1/2" of close cell. However if you have 2 x 4 walls you will have an R-12 with 1/2 pound and an R-17 for 2 1/2 inches of 2 pound. Many recommend 1/2 pound for cathedral ceilings because if your roof leaks it will penetrate through the 1/2 pound foam letting you know you have a roof leak, with the 2 pound it will trap the moisture not letting it through and possibly rotting your roof. An advantage of 2 1/2" of closed cell is you can still fish electrical in your walls at a later point if you have a 2 x 6 wall.
Back to TopYes, significantly racking tests done by NCFI have shown to add as much as 40% to the strength of a stud wall system. When hurricane Andrew went through Florida several homes sprayed with urethane held where as many homes built with out foam failed! NCFI Wall Strength
Back to TopFiberglass allows air to flow through it, spray foam does not. This is the one aspect which sets spray foam apart from fiberglass. Studies from the Energy Department have shown that air infiltration plays a big a part in energy loss. Air infiltration is amplified by pressure differences from the inside to the outside a home driving air leakage through the tiniest cracks causing significant heat loss. Fiberglass also allows air to move within the stud cavity, when the temperature is warm on one side than the other a convection loop starts to occur allowing air to move in a circular flow allowing more energy loss to occur. This is why many people feel drafts in there home or they can feel air flow at electrical outlets. With spray foam it stops any air infiltration and air movement. This is the main reason you can save up to 40% in energy costs. Take a look at Corbonds website and view three diagrams the "Insulation Performance Comparision", and both details "Ganser's six mechanisms" Check out this page from Corbond NCFI - Principles of Heat Transfer NCFI - Case Study RLC Engineering Paper
Back to TopNo, fiberglass needs venting because air flows through it and venting keeps it dry. With spray foam you do not need venting because the air does not flow through it and it is a moisture barrier as well! Unvented Cathedral Roofs
Back to TopNo, fiberglass needs venting because air flows through it and venting keeps it dry. With spray foam you do not need venting because the air does not flow through it and it is a moisture barrier as well! Venting Crawl Spaces
Back to TopR-value only measures conduction, it does not measure air penetration, convention, and radiation loss. This is why spray foam performs 60% better having the same R-value. R-Value Myth
Back to TopThere has been a lot of testing and case studies dealing with the performance of spray foam read the articles and visit there web pages below. 40 % Energy Savings
Back to TopBoth 1/2 pound open cell and 2 pound closed cells are excellent buffers for sound transmission. However the 1/2 pound open cell absorbs sound somewhat better than closed cell. It works excellent it your near a railroad tracks or by a highway. Some builders will use it on interior walls between bedrooms and bathrooms. We have used around and underneath entertainment rooms and in between floors underneath joists.
Back to TopThe up front costs of spray foam is about three times more than fiberglass however because spray foam is 40% more efficient the pay back is 5 to 6 years. You can also save in other ways, your builder can use 2 x4 walls instead of 2 x 6 walls on the exterior wall saving on lumber costs. Plus you will save on the extension jambs for all the openings. Along with this you can down size on your heating and cooling systems.
Back to TopSpray foam is install at the same time as other insulations would be. After the mechanical work is done and inspected and before the drywall is installed.
Back to TopSpray foam can only be installed when the ambient and surface temperature is above 40 degrees. Our experience has shown if the outside temperature is 25 degrees with light winds and you heat the roughed in home with a 200,000 portable propane heater you can get a home up to temperature in 2 1/2 hours. We use a inferred temperature gun to check the surface temperature
Back to TopAll the windows and doors must be covered, any holes to the outside must be patched in with a material to spray two. If there is any equipment or construction materials in the area they must be cover. The electrical wiring must be stapled securely at least 1 1/2 away from the outside stud surface. As far as how long a typical home take two days to install.
Back to TopInjection foam is totally expanded at the nozzle tip. Spray foam expands after the nozzle tip. Injection foam is simply plastic coated air bubbles, Spray foam is two chemical components sprayed at 1500 psi under high heat. Injection foam can be injected in a concealed space. Spray foam must be sprayed in a open cavity.
Back to TopYes, the chemical compositions are different, some contain a higher plastic content which works better in the colder wetter months. Some come premixed and some you have to mix in your own batch mixer. Some contain a chemical called resorcinol which can cause staining!
Back to TopSome states allow for what is call a parallel path method of R-value calculation. Wisconsin and some other states only allow what is called a series parallel calculation. The series parallel is actually the accurate method because it allows for the heat loss in the cross webs of masonry units? R-Value Controversy
Back to TopOne should not inject when the inner core of a masonry unit is wet and saturated. This will only breakdown the foam at that surface and cause leaching. Foam should not be installed when the ambient temperature is below 40 degrees, the foam will not set fast enough and collapse causing wet wall.
Back to TopThere are a couple of brands of foam which contain a chemical called resorcinol. If this foam is injected when the walls are to wet is can cause leaching bringing this chemical to the surface. Then after a couple of months the suns UV rays will turn the surface brown. This can occur even through paint as well. Fortunately is can be removed with a special chemical cleaner and a hot water pressure cleaner. MasterFoam does not use any foam with resorcinol in it. Brown-Staining Problems
Back to TopFoams will add about 1/2hour to a masonry wall, however most manufactures will not recognize there product as a fire rated component. One manufacture claims there product will add two hours to a 12" wall. The only problem is the testing they had been done with a wall grouted 32" on center vertically and horizontally. This wall would add two hours with out the foam because the grouting stops the air flow within the wall. Foam and Fire Rated Walls
Back to TopInjection foam is non corrosive and because foam encapsulates metal ties no air can get to it to cause corrosion. Plus in Wisconsin all masonry reinforcing must have a Class 3 galvanizing on it's surface.
Back to TopNo if is not flammable however because it is plastic coated bubbles it will melt.
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