Should I vent my attic?
A vented attic is, without a doubt, the most hostile environment in a building. It can reach temperatures of over 150° in the summer and be well below freezing in the winter. Any system that must operate in such an environment must work very hard just to overcome the temperature extremes. A vented attic also allows hot humid air to accumulate in the attic space and often times create a condition where the vapor condenses inside the attic. This moisture along with air and all sorts of cellulose materials are the three basic items needed for the growth of mold. Venting can also allow blowing rain and snow to enter the attic and accumulate on the attic floor or ceiling, possibly causing damage to the sheet-rock.
Converting attics into a semi-conditioned space in hot climates by closing soffits, gable and ridge vents is a positive design approach in reducing the moisture loads in houses and buildings. By applying Spray Polyurethane Foam to the roofline and making the attic area part of the conditioned space, you can overcome these problems and will enhance the operation of various systems located in the attic. Moving the duct system from an unconditioned area into the conditioned space has a drastic effect on its performance since its insulation is typically an R-4 to an R-6.
Any leakage on the supply side of the system is kept inside the conditioned space and isn’t lost to the exterior world. In a vented attic, any air leakage will allow hot humid air, along with dust and allergens, to be sucked into the ducts and circulated throughout the house.
New construction homes/buildings can achieve on average a 7-10° difference in temperature from the conditioned living space to the attic by means of Spray Foam's complete thermal package (insulating all exterior walls and roofline of the conditioned space). For example, a living area of 75° with a complete thermal package would have an average attic temperature of 82-85°. New/existing homes/buildings that only insulate the attic with SPF can reduce the attic temperature by an average of 30-45°.
Vented vs Unvented Attic
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Properly sealed, moisture-protected, and insulated walls help increase comfort, reduce noise, and save on energy costs. However, walls are the most complex component of the building envelope to insulate, air seal, and control moisture.
The keys to an effective wall are:
Airtight constructional air leaks sealed in the wall during construction and prior to insulation installation.
Moisture / rain drainage system, continuous air barrier, and vapor barrier located on the appropriate side of the wall.
Complete insulation coverage
Advanced framing to maximize insulation coverage and reduce thermal bridging, no gaps or compressed insulation, and continuous insulated sheathing.
Spray Polyurethane Foam (SPF) insulation is rigid, lightweight, flexible, wind resistant, and effective in extreme temperatures and weather conditions. SPF insulation has the highest R-value per square inch of any commercially available insulation material.
Total Comfort Control, Not Just R-Value
The building envelope is a system of construction components which protect against the uncontrolled movement of: heat, air, and moisture. The true performance of your building envelope can not be measured with the R-value of the insulation alone, but must also consider air movement, moisture control, health, safety, durability, comfort, and energy efficiency.
This is true whether your building is commercial, residential, or multifamily: SPF addresses all these needs in both new construction and improvements to existing structures. Six Mechanisms of Heat Loss Through a Wall or Ceiling That Are Bad for Your Home and Your Health:
Infiltration (Wind Pressure)
Intrusion (Wind Wash)
Moisture Accumulation (Humidity, Dew, and Frost)
Did you know?
Air infiltration can increase energy costs in buildings 10 to 40%. Adding Spray Foam Insulation has numerous benefits, including:
reduces air infiltration allowing insulation to be more effective and reducing the demands on HVAC equipment.
reduces moisture infiltration by reducing air leakage.
adds structural strength to walls and ceilings.
reduces sound transfer into buildings. Most sound from outside the building is carried into the building through cracks and air leaks. SPF by stopping the air infiltration also helps keep sound out.
minimizes dew point problems and condensation.
resists heat transfers through air infiltration regardless of flow direction.
provides reliable R-values under the most extreme conditions, dependable and durable protection against heat loss or gain.
minimizes thermal bridging, which can cause higher energy usage and cost.
out-performs conventional insulation materials because they trap still dry air and if that air moves or becomes wet, the thermal resistance can drop by 50%.
According to ASHRAE, a 3% void area in a wall cavity represents a 15% reduction in wall R-value.
Sloped, vaulted, and cathedral ceilings are different names for essentially the same ceiling configuration. These ceilings are very popular in newer homes and remodeled homes, and they certainly add dramatic visual interest to a room. But because there is little or no attic space separating inside and outside air, proper insulation is especially important.
If the crawl space in your home is not fully sealed, there is a strong likelihood that contaminated air, earth gases, mold, rodents, and more can penetrate your living space.
Spray foam insulation installed between your floor joists in your crawl space is the only material that will create an effective thermal barrier from obstructions such as wiring and plumbing, duct work, and narrow or wide joist spacing.
Batts are often compressed during installation due to the use of wire insulation hangers. Open web floor trusses create additional problems in that the open webs create pathways for air to move around the batts. During the summer, warm humid air can flow around the batts and create condensation, mold and decay problems in the floor system. Open web floor trusses are virtually impossible to adequately insulate with batts.
Closed-cell spray foam serves as an effective moisture barrier between the ground and homes subfloor surface. It will also prevent “stack effect” air/moisture movement into the homes walls and upward into the homes attic space, which can cause even more problems.
Spray foam circumvents floor insulation problems through its ability to completely fill voids and open spaces. Areas around wiring and plumbing as well as open webs of floor trusses can be completely filled, resulting in a complete, essentially uniform thermal barrier on the floor.
Spray foam insulation in the crawl space is a superior insulation product that overcomes several disadvantages of other insulation products. Spray foam can provide a more uniform, consistent thermal barrier.