We are asked many questions about the new energy code, and how to avoid common violations that we see regularly out in the field. We wanted to take a little time to share some images and information on the most common violations, and how to correct and avoid them.
We hope this helps!
A. PROPERLY BLOCKING AND SEALING KNEE WALLS THAT BACK UP TO UNCONDITIONED SPACES, SUCH AS ATTICS OR PORCHES.
Unless you are using open cell or closed cell foam as your insulation source, all knee walls or raised ceilings that separate conditioned space from unconditioned space must be blocked and sealed. This can be done by your framers with any type of material (OSB, Plywood, Foam Board, T-Ply). Once the back of the wall has been blocked, then it should be sealed with foam caulk, zip tape, or the like. This creates an air barrier and continuous thermal boundary to your “sealed” envelope, which is required by the 2015 IECC code, and will also greatly improve your blower door readings. We need to treat these walls like exterior walls, including sealing all penetrations.
NOTE: If you foam your houses and decide not to foam your attic ceiling floor, then you will also need to block and seal any knee walls that separate the condition spaces from the unconditioned spaces. There cannot be a break in the thermal envelope.
B. EAVE BAFFLES IN VENTED ATTICS.
The code states that when you have a vented attic, that you must install eave baffles adjacent to each soffit vent and window. This lets the soffit vents pull the air from the attic over the top of the blown or batted insulation without restricting the air flow. Should you choose to install vented soffit, you would need to install an eave baffle between every rafter. NOTE: This is not required with foamed ventless attics.
C. HOT WALL SHOWERS AND BATH TUBS.
The code requires that showers or bath tubs that back up to exterior (hot) walls have an air barrier installed between the fixture and the wall, and of course insulated behind them. The code also requires that the adjacent walls be insulated on any hot wall tub or shower. This once again creates a continuous air barrier with no breaks in the thermal boundary. Any material such as T-Ply can be used to block and seal this area prior to installing the fixtures. Another way to avoid this issue is by designing the house without hot wall showers or tubs. THIS DOES NOT APPLY TO TILE SHOWERS BACKED WITH HARDIE BOARD OR GREEN ROCK, OR TO ANY FIXTURE WHERE THE EXTERIOR WALLS ARE FOAMED.
D. PROPERLY SEALING THE FLOOR PLATES TO THE FOUNDATION.
The code requires that all floor plates be sealed to the foundation. This must be done on all houses, in addition to any optional foam gasket under the plates, which is also recommended.
E. PROPER SEALING OF ELECTRICAL, MECHANICAL AND PLUMBING PENETRATIONS.
The code requires that all penetrations separating conditioned space from unconditioned space be sealed. This would include exterior walls, and all top plate penetrations on non foamed houses. (The municipal inspector could require this on all top plates in any home as a fire retardant).NOTE: If you are foaming your walls or rafters, just be sure that the installer seals any and all penetrations with the foam insulation.
F. SEALING CAN LIGHTS, ELECTRICAL BOXES AND AIR REGISTERS TO DRYWALL AT THE CEILING.
The code requires that there be some type of air sealing around the air, mechanical, and electrical penetrations between conditioned and unconditioned space. This can be done with any type of fire proof sealing caulk or gasket. Our goal here is to eliminate any infiltration or exfiltration of air between these areas. NOTE: If you are foaming a ventless attic this will not be required, as the attic would be considered condition space.
Thank you for your business!. Our goal is to help bridge the gap between the builder and the energy code.
Kaleb and Scott Moody
K & S Energy Group, LLC
903-271-9878
WWW.KANDSENERGYGROUP.COM
“Seal tight - Ventilate right!”