Is spray foam a good idea for my new build?
11 years ago
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- 11 years agolast modified: 9 years ago
- 11 years agolast modified: 9 years ago
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My Spray Foam Experience (Very Long post)
Comments (6)water- congrats on building an efficient home. its good to see results and suggestions taken by the pros that offer it up on this forum. Jen Tight homes need to have correctly sized hvac for it. There are very few mechanical guys that know how to size units for tight homes with very low air leakage. Most "rule of thumb" sizing does not work. The large units short cycle and do not run long enough to extract the humidity out of the air like you mentioned. Smaller units will have longer run times, correct, but they will run at a much lower speed so the energy usage is lower and the house maintains better. My home is an ICF home with similar r value (r 28 average and r60 attic with some r50 foamed rafters) and air tightness with triple pane windows only uses a 2 ton AC unit. The square footage is about 3800 total conditioned space. In zone 6 with 7200 HDD, the furnace is a Lennox modulating that ranges from 22k btu to 70k. It runs around the 25k for most of the time in the winter at 0 and below. Rarely does it ramp up to full speed ever. The mechanical was carefully designed and selected, and there is also an HRV installed. The full mechanical, high end equipment and HRV only cost $12k for the home nearly 4k sqft. I have seen people post numbers on here that are over double that in dollars and sizing for the same square footage. This is due to some or all of: code min. home design and construction and/or oversized hvac. Now, its great the spray foam is performing, but without starting the debate, I just want to be clear to any readers that they are other methods of achieving a tight home, high r, and the same results as the poster WITHOUT using spray foam, all at a reduced cost of spray foam. And as always, put the money into the shell of the home, not the hvac! Increase the shell, decrease the hvac. Most cases, dollars are a wash or less and energy usage is lower for the life of the home!...See MoreSpray foam worth it in my situation?
Comments (12)That's a tough one, since I don't, nor do most people I see who mention ROI, have good variables with this. I am an analyst to the core, but quite frankly nobody can tell me for sure what my monthly heating/cooling bill will be WITH the sprayfoam and what it will be WITHOUT it. I've asked the HVAC guys, the York guys, the insulation guys (all 4 of them), and NONE could give me a good analysis to show the true savings. I've seen spray foam "cuts bills by 20%!" or "saves up to 40% on monthly bills" etc. but nobody ever backs up those figures. e.g. just google "savings from sprayfoam" and you'll see.. "The US Department of Energy (DOE) studies show that 40% of your homeâÂÂs energy is lost due to air infiltration" OR "Monthly energy and utility savings of 30% or greater can be achieved when compared to the alternative roofing and insulation systems. The cost of an SPF roof or insulation system can often be recovered in less than 5 years, simply through energy savings alone." But no figures ever back that up. SO, I set up a simple spreadsheet in Excel, with inputs of 1. Monthly utilities without sprayfoam 2. Expected savings and 3. Sprayfoam cost. It allows me to input different variables and see results. My situation is especially tough b/c the house is new and I don't have any "current" utility bills. But what I did have was use my old house bills, which admittedly was smaller, had 2x4 framing, and was no doubt not as tight. But I had my old bills and then added on some increased costs to account for the larger 3200 vs 2000 square feet, and the increase due to TYPE of utility.. going from natural gas to electric heatpump and propane (3x the price of the NG I used to have). The tough thing is knowing how much of those utility bills are heating/cooling vs. lights/dryer/water heater etc. (things that won't get affected by sprayfoam). So I assumed I'd have around $350 in monthly (average heating/cooling) costs, and assumed I'd save 20% due to sprayfoam. That is $70 a month. For a year, that's $840 a year. $5300/840 = 6 years or so ROI. Using a 30% savings led to a 4 year ROI. Using 10% led to a 12 year ROI. Furthermore, assuming a lower $300 monthly utilities, the ROI is.. 10% = 15 years 20%= 7 years 30% = 5 years Assuming $250, its 17 years, 9 years, 6 years. Knowing that I plan to be in this house for 20+ years, and that I expect utility costs to go up faster than inflation, for me, the cost made sense....See MoreRigid foam vs. spray foam under crawlspace
Comments (12)love this forum that you can do a little diy advising! ok the mold in the supply boxes and on the grills probably isn't from the duct takeoffs @ the plenum. it takes a long time for mold to travel that far..and if there isn't moisture & food source it won't spread to that area. it isn't always mold..sometimes it is just dust. so mold/dust buildup at the ducts @ plenum is lack of proper air seal. mold in supply boxes & on grills is lack of proper air seal at the cut in the sheetrock ceiling where supply grill is attached to the box. nine times out of ten..you can solve the issue by sealing supply boxes to sheetrock. see attached picture. hardcast brand #1402 mastic tape is used to seal supply box to sheetrock. this tape is 3" wide. I split the 3" into 1 1/2" lengths. stick to sheetrock and fold into supply box. as the tape adheres to many surfaces you need to be careful to keep it within the area covered by the supply grill. once it sticks to the sheetrock..you'll lose paper if you try to move it. surfaces have to be clean & dry for tape to adhere. and once in place you'll want to press it in place as it is somewhat pressure sensitive. the tape is strong enough to keep the box tight to attic floor on the attic side when installing the supply grill. wash the dust off the grills, wipe inside the supply box & into the duct. reinstall the supply grill. oh and when you remove the supply grills..take a sharpie and mark what direction they faced (throw to window..dirveway side whatever note you need to put them back in same position) this way you'll put them back as they were. I've tried several other brands of mastic tape. hardcast 1402 is the best. the others are 2" width and mastic is thinner, resulting in less strength and useful life. why would I chose spray foam for my floors? I've sealed floors several ways, foam is the easiest albeit more costly, once prep work is done. there isn't enough room to physically install foam sheathing to the bottom of the floor joists. I'll seal any big holes..like under tub then do 3" foam. I've looked at froth packs like tiger foam..but having worked with so many foam companies locally, will just have them do my floor when they are in my area. the software is pricy. we lease it yearly. once upon a time we bought the cd..but too many people abused it. so now it is a download & upgrades to original install. a lot of mastic isn't always an indication of a good seal. it doesn't take a lot if you put it in the actual leaks. you can feel around the duct take offs on the plenum while unit is running and feel some of the leakage. also checking plenum connections to the equipment at the same time. I use mastic tape to connect plenums (after screwing them in place) much easier to seal under the plenum to equipment with tape than painting mastic upside down....See MoreFoam Board Insulation after framing.. Place it and spray foam edges?
Comments (18)No such machine was used... They poured the entire garage at once which lasted from 8:15am-8:45am.. From that point until 1pm they were working the concrete by hand.. This is a quick shot of what they were doing: I just really can't believe that this company would allow this.. They are a higher end company and they do most of their work in high end neighborhoods.. I am actually getting a little concerned that its not even.. I went over while at work to take a quick pic but got their late and it was already dark.. I left the headlights of my car on and took a pic.. I can't tell if its the lighting combined with the trowel marks, but it almost looks like ripples.. This is what it looks like: At this point I don't know what to even do.. I feel like every time they get to the next stage I have to question what my options are because it wasn't done right.. I know I am not building a mansion or some multi million dollar home, but I just feel like I probably could have done a better job myself and I have absolutely no experience.. I know it's easy to second guess people, but I feel like this is not an acceptable finish.. I talked with a few people and they said there is no real way to "repair" this.. They would have to hammer it all out and pour again.. I had contemplated doing an epoxy finish but I don't even know if that would solve this.. Im sure it would help the finish look, but if this floor is in fact not level I am not sure an epoxy coating will level it out.. I am nervous to even go down to the basement.. I only saw a small portion from the upper level (no stairs installed yet) and everything was covered.. I can only assume the basement slab looks the same.....See MoreRelated Professionals
Asbury Park Architects & Building Designers · Johnson City Architects & Building Designers · Madison Heights Architects & Building Designers · Syracuse Architects & Building Designers · Bloomingdale Design-Build Firms · Accokeek Home Builders · Anchorage General Contractors · Columbus General Contractors · DeRidder General Contractors · Evans General Contractors · Hutchinson General Contractors · Plano General Contractors · Port Washington General Contractors · Shorewood General Contractors · Woodland General Contractors- 11 years agolast modified: 9 years ago
- 11 years agolast modified: 9 years ago
- 11 years agolast modified: 9 years ago
- 11 years agolast modified: 9 years ago
- 11 years agolast modified: 9 years ago
- 11 years agolast modified: 9 years ago
- 11 years agolast modified: 9 years ago
- 11 years agolast modified: 9 years ago
- 11 years agolast modified: 9 years ago
- 11 years agolast modified: 9 years ago
- 11 years agolast modified: 9 years ago
- 11 years agolast modified: 9 years ago
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