Questions Of The Week for 17 June 2019

**** Welcome to another round of Questions of The Week!

Please read the Introduction and requirements, changes may have been made.

A member of the Awards Committee will post questions, at a random day/time.

The competing members may make one post per question thread to answer the questions and the member’s winning entry must have all parts of the questions answered completely in that one post. Editing your one answer post allowed will result in disqualification.

Any disregard to the above and divulging the correct answers or giving hints/references will cause a disqualification.

First correct answers (as judged by the Awards Committee or Poster of the Questions) wins.
The lucky winner will get a case of “Now that you’ve had a Home Inspection Books” shipped to them at their address on file. Make sure your Address on File with INACHI is correct.
Winners of the Questions of The Week shall request their prize by emailing fastreply@nachi.org and submitting their Mailing address for shipping.
Allow 2 weeks for delivery.

GOOD LUCK! ~ GO! :cowboy_hat_face:

1. Why is “transpiration” an important concept for Home Inspectors no matter what part of the country you live in?

2. When creating isolation joints between flatwork and foundation what type of material should be used as a spacer between concrete pours?

3. What must be performed if a purlin vertical brace exceeds 8 Feet in length?

4. When asphalt shingles are packaged they are equipped with a thin strip (typically a polyester film) that is placed on the top shingle side. What is the purpose of this strip and how should it be dealt with during shingle installation on the roof?

5. For proper attic ventilation of 1/300 (building code based alternative to minimum ventilation) of a 3000 Sq. Ft. attic, with a 7/12 Pitch roof, with 50% input and 50% exhaust opening space, how many 6” X 16” soffit vents with 42” of Net Free Area each are required and how many static/passive vents near the ridge with 61” of Net Free Area each are required?

Extra credit question. This question will be used as the fifth correct answer if nobody answers all five above but does answer four of the five.

6. What are the six finish levels for gypsum board and why is it important to know these?

Great questions, Manny!

And, thanks.

I know I know. :exploding_head:

  1. hot & sweaty attics can kill!
  2. MY PILLOW!

mikey
3) OJ Simpson phone call
4) trick question ~ no thin strip
5) just do up a whole house fan so you don’t have to do all that math!
6) I dunno ~ never started to FINISH

And I thought these would be hard questions. :stuck_out_tongue_winking_eye:

Very good Manny and funny Marc.

Excellent questions Manny. I did not know there are 6 finish levels for drywall, we just have **********, ***** and ******** here in New Mexico :smile:

In the scale 0 to 5 if 0 is level 1 so 5 is level 6 - skim-coat
In the scale 0 to 5 if 0 is level 0 so level 5 is the skim coat and the next level (6) is the primer (sealer).
In my opinion at least primed drywall should be considered as finished surface.
Unsealed compound and gypsum board will absorb moisture and deteriorate.

1.Transpiration is the process which moves water through a plant from the ground and into the air. This can affect interior and localized exterior humidity levels which may affect mold growth.

  1. Asphalt fiber board.

  2. A 2x4 brace must be changed to a 2x6 brace with a 2x4 “T” that goes all the way to the top of the 2x6 brace and must come to within at least 6" of the bottom.

  3. To prevent shingles from sticking together while they are still in the bundle - in storage. Leave it on!

  4. 35 and 24

  5. LEVEL 0: No taping, finishing, or accessories required

LEVEL 1: All joints and interior angles shall have tape embedded in joint compound. Excess joint compound, tool marks and ridges are acceptable.

LEVEL 2: All joints and interior angles shall have tape embedded in joint compound and wiped with a joint knife leaving a thin coating of joint compound over all joints and interior angles. Joint compound applied over the body of the tape at the time of tape embedment shall be considered a separate coat of joint compound and shall satisfy the conditions of the level. Fastener heads and accessories shall be covered with one (1) coat of joint compound. Surface shall be free of excess joint compound. Tool marks and ridges are acceptable.

LEVEL 3: All joints and interior angles shall have tape embedded in joint compound and shall be immediately wiped with a joint knife leaving a thin coating of joint compound over all joints and interior angles. One (1) separate coat of joint compound shall be applied over all joints and interior angles. Fastener heads and accessories shall be covered with two (2) separate coats of joint compound. The surface shall be smooth and free of tool marks and ridges.

LEVEL 4: All joints and interior angles shall have tape embedded in joint compound and shall be immediately wiped with a joint knife leaving a thin coating of joint compound over all joints and interior angles. Two (2) separate coats of joint compound shall be applied over all flat joints and one (1) separate coat of joint compound shall be applied over interior angles. Fastener heads and accessories shall be covered with three (3) separate coats of joint compound. The surface shall be smooth and free of tool marks and ridges. Where glass mat and/or fiber-reinforced gypsum panels are installed, refer to the gypsum panel manufacturer for specific finishing recommendations.

LEVEL 5: All joints and interior angles shall have tape embedded in joint compound and shall be immediately wiped with a joint knife leaving a thin consistent coating of joint compound over all joints and interior angles. Two (2) separate coats of joint compound shall be applied over all flat joints and one (1) separate coat of joint compound shall be applied over interior angles. Fastener heads and accessories shall be covered with three (3) separate coats of joint compound. A thin skim coat of joint compound or a material manufactured especially for this purpose shall be applied to the entire surface. The surface shall be smooth and free of tool marks and ridges.

It is important to know what the final finish result that the client desires, because the cost increases as the finish level increases.

Good Questions Manny! Thanks for your time!

Aww no more takers? Steve is GOOD but there is still a chance!

Shucks, that right there is worth more than a case of books to me! Thanks Manny!

Awww what a bummer, no other takers! Looks like Steve Nadeau has taken this round and won the prize!! Good Job Steve!!

Your answer to question 1 was a much less common issue than I have for the answer but it is nonetheless a very real possibility. Your answer was a flashback many years ago and the only easily verifiable cause of high interior humidity levels I have encountered. That house was covered over with trees, on the sides with shrubs, AND ivy growing from ground to over the eaves on almost the entire house. It was like a sauna inside on the Summer day I inspected and plenty of mold growth and other moisture problems.

Your answer for #3 is also more in depth than I was expecting but a sign of good framing!

You definitely know the calculations for attic ventilation but used the 1/150 calculation instead and left out the last step of halving the required number of vents. However you get this right since you know the calculations needed.

These are the answers I have for the questions.

1. Why is “transpiration” an important concept for Home Inspectors no matter what part of the country you live in?

A. Transpiration (shortened description) is the process where a plant will absorb water from the surrounding soil through its roots and then eventually emitting water vapor through stomata in its leaves and in its stems and flowers. Some vegetation can emit more than others. For example a large, mature oak tree can emit 100 gallons a day where a maple tree over 50 gallons a day. Taking this much water out of the soil around a home’s foundation and/or retaining walls can create significant issues in areas with expansive soils. In all areas (expansive soils or otherwise) this can rob the soil of moisture needed to grow ground cover. A lack of ground cover can contribute to erosion of soils around foundations and retaining walls.

2. When creating isolation joints between flatwork and foundation what type of material should be used as a spacer between concrete pours?

A. A compressible material should be used between pours to allow concrete to move slightly if needed and prevent damage to either pour side. These materials can be asphalt impregnated fiber sheeting or one of the other compressible products used for this purpose. A good description for this can be found on the ConcreteNetwork site https://www.concretenetwork.com/concrete-joints/isolation-joints.html .

3. What must be performed if a purlin vertical brace exceeds 8 Feet in length?

A. The vertical brace must itself also be braced. This is specified in the IRC section R802.4.5.

R802.4.5 Purlins. Installation of purlins to reduce the span of rafters is permitted as shown in Figure R802.4.5. Purlins shall be sized not less than the required size of the rafters that they support. Purlins shall be continuous and shall be supported by 2-inch by 4-inch (51 mm by 102 mm) braces installed to bearing walls at a slope not less than 45 degrees (0.79 rad) from the horizontal. The braces shall be spaced not more than 4 feet (1219 mm) on center and the unbraced length of braces shall not exceed 8 feet (2438 mm).

4. When asphalt shingles are packaged they are equipped with a thin strip (typically a polyester film) that is placed on the top shingle side. What is the purpose of this strip and how should it be dealt with during shingle installation on the roof?

A. The placement of this strip coincides with the location of the shingles self sealing strip on its bottom. Its purpose is to prevent the shingles from sealing together prior to installation. When properly installed these thin packing strips should not be visible and should not cause issues with the shingles sealing down. As a result they do not have to be removed and can be left in place. National Roofing Contractors Association (NRCA) Roofing Manual: Steep Slope Roofing Systems is your guide for this item.

5. For proper attic ventilation of 1/300 (building code based alternative to minimum ventilation) of a 3000 Sq. Ft. attic, with a 7/12 Pitch roof, how many 6” X 16” soffit vents with 42” of Net Free Area each are required and how many static/passive vents near the ridge with 61” of Net Free Area each are required?

A. Why try to calculate something like this??? Instead use the Air Vent calculator found on their site at http://airvent.com/ventilation-resources/attic-ventilation-calculator. You can download a PC based spread sheet or if you want on site answers they even offer an app for smart phones. The answer is 21 total soffit vents and 14 total static/passive vents using the Air Vent calculator and 18 Soffit vents and 12 Passive vents (rounded up) when calculating manually. Keep in mind that the 1/150 or 1/300 are the minimum ventilation and as can be seen Air Vent calculates slightly higher which is completely acceptable to do.

Extra credit question. This question will be used as the fifth correct answer if nobody answers all five above but does answer four of the five, or as a determination of the winner if more than one person answers all five above.

6. What are the six finish levels for gypsum board and why is it important to know these?

A. The six finish levels, along with a great deal of important information can be found in the USG The Gypsum Construction Handbook, Chapter 5, found here https://www.usg.com/content/usgcom/en_CA_east/resource-center/gypsum-construction-handbook.html . Also on this site there is much more valuable information to be had! It is important to know how gypsum is applied and finished so that you can advise a client if a visible installation defect can possibly be corrected without a total removal and replacement of the gypsum board.

Congratulations Steve.

Congratulations, Steve! :smile:

Thanks, I’ve given up trying to win the books - I just play to sharpen my shovel. The times I do win and beat out the rest of you smart guys, is just a bonus.

Now where’s the next round of questions? lol

That’s the spirit, Steve! :smile:

Congratulations Steve! I thought you got them right.