Damn, I got more than 2 wrong?! I can’t wait to see these answers haha. This was a tough week.
Darn no winners this week. For those that tried great job!! For those that did not you should jump in and give it a shot.
This week’s question theme was obviously energy efficiency as noted by the question line. These were all from one home recently inspected. When I return for the final home inspection I have an advantage that I know what might be going on behind the gypsum board and brick/stone. However when you’re inspecting an existing home or just the new home final you won’t have any idea what’s going on behind the gypsum board. Having an understanding how a home is built might help shed light on what you are seeing. Obviously you can’t report on something you don’t know or can’t see but it may well point you in the direction of other issues or a combination of issues.
- With reference to energy conservation and construction what are the answers to the following questions.
• What is the “Continuous Air Barrier” and its purpose?
• Where is the “Continuous Air Barrier” located?
Answer: A very good and simplified explanation with answers to these questions can be found here https://basc.pnnl.gov/resource-guides/continuous-air-barrier-exterior-walls#quicktabs-guides=0.
- If a Builder is using National Shelter Products TSX Dryline sheathing, and/or Fibre Converters Thermo-Sheath sheathing, and/or Ox Engineered Thermo-Ply Sheathing as an “Air Barrier” method what step must be taken with these products to qualify as the “Air Barrier?
Answer: All sheathing panel edges at the top and bottom of the wall assemblies, and all joints between sheathing panels, shall be sealed with an approved construction tape. This can clearly be seen in the Engineering reports for these products and the applicable building code section(s) with links and displayed here.
• Thermo Sheath https://www.fibreconverters.com/markets/housing
• Dryline TSX http://www.nationalshelter.com/products/construction-materials/dryline/tsx/
• Thermo-Ply https://www.oxengineeredproducts.com/product/thermo-ply/
IRC N1102.4, N1102.4.1, N1102.4.1.1 - These are the requirements for the air barrier function of the sheathing. Of most importance is N1102.4.1.1 which specifies the materials are required to be installed per the manufacturer requirements to satisfy their air barrier function. These sheathing manufacturers require proper flashing/sealing tapes to be used on their products.
- With the listed sheathings above which of the following seam tape(s) are acceptable for use?
A. Protecto Wrap Company’s Super Stick Synthetic Butyl Building Tape
B. Owens Corning HomeSealR Foam Joint Tape
C. Dupont Tyvek Wrap Seam Tape
D. Henry Company Fortiflash Tape
E. 3M Multi Use Duct Tape
Answer: A & D are the only tapes listed above that are approved as seam sealers for the sheathing listed above. The remainder are specialty tapes manufactured for that manufacturer’s specific products or plain old Handy Andy tape. Dupont actually makes a construction tape, other than their Tyvek tape, that is used for this purpose and general flashing around windows and doors.
Keep in mind if you do see something over and over again it does not necessarily make it right. It just might mean they have been doing it wrong over and over again. No matter what it is if it looks wrong take pictures and notes and check it out thoroughly later when you’re doing your report.
- The following are the particulars for this build. Given these particulars what is the problem at the stud bay pointed to by the arrow?
• This is the second floor.
• Walls are 2 X 4 at 16” On Center
• The foamed lines are for two air conditioning condenser units that sit outside of the first floor wall below this.
• Winter design temperature is 22 Degrees Fahrenheit.
• Wind Design speed is 115 MPH for 3 Second Gust and 76 MPH Fastest Mile
• Continuous insulation value required in external walls is R20 or R13 + R5
• Mean Annual Temperature 64.9 Degrees Fahrenheit
• Weathering Amount – Moderate
• Frost Line Depth 6”
Answer: I admit this was a little tricky. I added a bunch of information that just wasn’t needed. All that was needed was the stud size, the required exterior wall insulation level, and what is occupying the bay (even though that isn’t really needed). The stud bay is 50% + filled with HVAC coolant lines, blocking wood, etc. As a result the required exterior wall insulation value can not be obtained in that stud bay. BTW that was a second floor with the lines going to the first floor with the same situation in that stud bay.
- At any access hatch or door leading from conditioned to unconditioned space, in general and barring any exceptions, what must be performed to ensure energy code compliance?
Answer: The hatch or door must be weatherstripped and insulated to a level equivalent to the insulation on the surrounding surfaces. This is spelled out in IRC N1102.2.4.
N1102.2.4 (R402.2.4) Access hatches and doors. Access doors from conditioned spaces to unconditioned spaces such as attics and crawl spaces shall be weatherstripped and insulated to a level equivalent to the insulation on the surrounding surfaces. Access that prevents damaging or compressing the insulation shall be provided to all equipment. Where loose-fill insulation is installed, a wood framed or equivalent baffle or retainer shall be installed to prevent the loose-fill insulation from spilling into the living space when the attic access is opened. The baffle or retainer shall provide a permanent means of maintaining the installed R-value of the loose-fill insulation.
Exception: Vertical doors providing access from conditioned spaces to unconditioned spaces that comply with the fenestration requirements of Table N1102.1.2 based on the applicable climate zone specified in Section N1101.7.
The following question is for extra credit. This will be used as a tie breaker between the first two people who answer all five questions (1 – 5) correctly or if nobody answers all five then the first two people who answer 4 of the questions (1- 5) correctly.
- These are obviously items you can not visibly see most time (barring possibly question #5). However why and when would it be important to know the answers to these questions?
Answer: For those of you performing Thermal Imaging you must know how homes are being constructed to help understand some of the anomalies that you encounter. For everyone, even on existing homes, you should be aware of how homes are constructed because your client may well know themselves and have questions regarding these. I deal with intelligent, detail oriented, and very observant clients and have actually had one ask about a similar situation to question #4 when they could feel the wide temperature variant when next to a similar situation as this. Obviously without tearing out the gypsum board you would not know for sure but you could provide a very educated guess if you understand how a home is constructed.
For #4 here in Texas we frequently encounter attic access points in second floor closets. These points have access covers that are usually gypsum board with a wood trim frame that has been nailed to the surrounding wall. Obviously we are not going to pull it off whether new or existing construction. However just placing your hand on it and the surrounding wall you can tell they did not insulated the back of the opening. Usually these are also in closets with no ventilation provisions which can always contribute to condensation issues in the closet.
WOW great stuff Manny!
I hope others, like I, will take the time to absorb your education. 
Thanks, Manny!
Hopefully, everyone learns something from your efforts, my friend. 
Thanks for your H-Bomb of information - very potent “thinker” questions.
Good stuff Manny! Thanks for your time and sharing!
Yeah definitely a hard week. Great topic though! Makes me think more about energy efficiency.