Dew point in wall calculation/calculator? - Fine Homebuilding
Clewless1 | Nov 25, 2010 10:28am | #1. Calculating the temperature at each layer of a wall is relatively easy to do. Most would assume that the RH inside would tend to drift outside ... increasing RH as it does. Making that assumption, the dewpoint would be easy to determine. But as Dan says ... the vapor transmission rates are difficult at ...
Choosing the Right Thickness of Exterior Foam
Rigid foam must be thick enough to prevent condensation on the roof sheathing. When combining exterior foam insulation with fiberglass, cellulose, or mineral-wool roof insulation, the foam layer must be thick enough to keep the sheathing temperature above the dew point. Otherwise, water vapor can condense on the back side of the sheathing ...
Closed-Cell Foam between Studs Is a Waste - Fine Homebuilding
Closed-cell foam is so dense that it is difficult to trim. To avoid having to trim closed-cell foam in a 2×4 wall, the installer will usually stop at a maximum depth of about 3 in., instead of the full 3-1⁄2 in. depth of the stud cavity. This leaves the typically bumpy surface of cured foam and about a 1⁄2-in. gap to the back of the drywall.
Insulating concrete block house - Fine Homebuilding
Jun 4, 2013 · The explanation the building science groups gave me as for why this was a bad approach are the following. The dew point, they said, would be where the warm indoor air meets the cold block on the backside of the foam. Then the water vapor dries to the outside, destroying the stucco by rotting out the wire lath and pushing off the paint.
Vapor Barriers Are a Good Thing, Right? - Fine Homebuilding
Aug 17, 2010 · Use a dehumidifier to keep the humidity below dew point. Stop breathing, sweating, cooking and washing to keep water vapor out of your home. Leave your home empty during cold weather. If you keep your indoor temperature at 70°f and your relative humidity 65% then dew point is 57°f. If you change your relative humidity to 45% then dew point is ...
Six Proven Ways to Build Energy-Smart Walls - Fine Homebuilding
Insulated with cellulose: R-36.0. • Optional 2×3 insulated wall and high-efficency fiberglass give potential for even higher R-values. • Large capacity for moisture storage allows the wall cavity to dry gradually. • Panels are often manufactured off site, trucked to site, and craned into place, which all add to cost.
Online Deck Load Calculators - Fine Homebuilding
Live Load: 30 lb. to 100 lb. choices in 10 lb. increments. Dead Load: 5 lb., 7 lb., 10 lb., 15 lb., and 20 lb. When you click “Calculate Maximum Horizontal Span” at the bottom of the entries, the system will give you the maximum span for the information you’ve entered. Because the calculator goes beyond the limits of grade, live load, and ...
How to Calculate Deck Cantilevers - Fine Homebuilding
Example: A deck with a beam located 12 ft. 6 in. from the ledger, framed with 2×10 joists at 16 in. on center. Check 1: The allowable overhang/maximum cantilever is 3 ft 5 in. per the DCA 6 table and 3 ft. 6 in. per the 2018 IRC table. Check 2: 12 ft. 6 in. / 4 = 3 ft. 1 in.
Insulating Cathedral Ceilings - Fine Homebuilding
May 17, 2012 · Synopsis: Cathedral ceilings provide a majestic crown for many a great room, but insulating them can be tricky. A poorly detailed cathedral ceiling can lead to energy losses and rotted roofing. In this article, senior editor Martin Holladay describes eight ways to get a cathedral-ceiling roof to R-45 or better using both vented and unvented ...
Insulating Scissors Trusses - Fine Homebuilding
When Matthew O’Malia, an architect specializing in high-performance buildings, designed a Passive House for clients in Michigan, he specified cellulose-insulated scissors trusses. Most of the ceiling area was covered with 28 inches of cellulose, although the insulation was somewhat thinner near the eaves. O’Malia’s details were ...