Our Insulation thoughts; what is the best financial investment to achieve the end goal of good insulation, good indoor air quality and sound control?

 After you’ve completed sealing the thermal envelope, what goes behind the drywall is a big decision. Let’s start with basics.

 INSULATION / R-VALUE

R-Value is a measurement of thermal efficiency or measurement to the resistance to heat flow. The higher the R-Value numbers the greater resistance the insulation has to the movement of heat.

A large percentage of heat escapes through the attic and walls of a home. In order to build a better thermal envelope, we accept that heat flows in one direction, from warm space to cold. Example, warm inside air will flow to the outside during winter months. The most common insulation method is fiberglass insulation batts, which are placed between the studs and stapled into place. The drywall is then nailed over, creating a wall. Although this is an acceptable method, it can be done better. The fundamental problem with the batt is you need to ensure there aren’t any gaps and you can’t because those insulating products are manufactured true and square. In a real-world environment, cavities between the studs are irregular and additional trades cause other obstructions like plumbing stacks or HVAC trunk lines.  You also have to work around supplementary roof and wall penetrations associated with utility and/or local communication companies that create hard-to-reach places creating pathways for conditioned air to leak in or out, sacrificing comfort.

Why Spray?

Because this delivers a continuous thermal and air barrier that seals around plumbing, vents and electrical openings as well as other cracks and voids that allow unwanted air leakage. Leaving no gaps or seams, it minimizes airborne irritants such as allergens, drafts, or humidity.

The following are spray-in custom insulation materials that provide superior performance in relationship to the above acceptable building method.  

Icynene insulation delivers advanced moisture management by forming an air seal to minimize air movement. By minimizing air transported moisture through the building envelope, Icynene helps to prevent condensation and reduces the potential for mold growth within walls and ceilings. Icynene products feature 100% water-blown technology. Using Icynene insulation in place of an air-permeable option can dramatically reduce a building’s carbon footprint by as much as 50% since less energy is required to heat and cool the building.

http://www.icynene.com/

Johns Manville Spider® custom fiber glass insulation is available in variable thickness levels. It  can fill 2x4 cavities up to an R-15 thermal rating, 2x6 cavities up to R-23, JM Spider® insulation also reduces sound transmission, achieving a Sound Transmission Class of 43 in a standard 2x4 wood-framed wall. JM Spider® insulation resists mold because it sprays in almost dry (less moisture content than wood framing), and is treated with a U.S. EPA-registered mold inhibitor to protect the insulation against mold. JM Spider® insulation can be used for both wall and ceiling applications. In addition, only fiber glass insulation made without formaldehyde—such as JM Spider® Custom Insulation—can pass Environmental Specification 1350, the toughest indoor air quality test in North America, with a non-detect for formaldehyde.

http://www.specjm.com/products/sprayin2/spider.asp

If you have additional questions on insulation, please contact us  @ info(at)cdbmd.com 

Cheers!!

We are currently preparing for close-in on one of our more unique and challenging custom homes. What makes it challenging? Two factors; it’s a significant renovation; which meant keeping the original foundation built in 1960 and then constructing a magnificent modern designed structure.

Our client is extremely concerned with energy consumption. To this end, we thought we would blog about “common household air leaks” and what to do. The main areas to address are:

• Behind Kneewalls
• Attic Hatch
• Wiring Holes
• Plumbing Vent
• Open Soffit (the box that hides the recessed lights)
• Recessed Light
• Furnace Flue or Duct Chaseway (the hollow box or wall feature that hides ducts)
• Basement Rim Joists (where the foundation meets the wood framing)
• Windows and Doors

At Congressional Design Build, we subscribe to the theory that if you insulate properly, you can heat and cool your house with a match … we’ll almost. Start by sealing the thermal envelope. This is part of the house which separates the indoors from the outdoors, and consists of the floor on the bottom level, the ceiling on the top level, the exterior walls, the exterior floor bands, and of course the doors and windows.

How?

• During the framing process make sure you seal under the exterior walls; we use a special wall gasket
• Use housewrap (tyveck or equivalent) on the exterior framing at the floor band just below the walls, and to the very top outside of the exterior walls. Follow installation instructions
• Caulk under exterior doors before installation
• Seal around windows and exterior doors using caulk or poly foam sealer (great stuff) that is specified for doors and windows. Don’t use the regular expanding foam sealant …just don’t!
• If your attic will have blown insulation, ask to build a box around the access hole so the insulation can come all the way to the access hole without spilling into the house.
• After wiring, plumbing and HVAC have been roughed in and before installation of insulation, use foam sealant in all of the holes that have been drilled through the top or bottom plates of all walls; not only the exterior walls. The interior walls are important too; air will exchange from the interior to the crawl space and the attic through interior walls.

We would recommend hiring an insulating company to perform the above and make it part of their Turn-Key solution. In the Washington Metropolitan Area they call it “Air Control and Draft Stop.” They typically use a foam sealant and a high grade non-sag caulk for air control and we would recommend an STI Fire Stop product.

Next we use spray-in custom insulation materials that provide superior performance, we’ll tell you who they are and why it’s superior on our next blog entry. 

Cheers, Team CDB