Questions of the week.

Inspection Education Topics Inspection Question of the Week
1

**
Questions of the week 10/30/2016**

Introduction and requirements:

A member of the Award Committee will post a question, at a random day/time.

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

Winnings will be limited to no more than 6 times in a given year, the objective is to allow as many Members a chance to win as possible.
Any disregard to the above and divulging the correct answers will forfeit the weekly winnings.

So please refrain from participating if you have already won in the maximum for the Year.

First correct answer (as judged by the Awards Committee or Poster of the Question) 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.

Courtesy of Nick Gromicko.

Winners of the Question of The Week shall request their prize by emailing fastreply@nachi.org and submitting their Mailing address for shipping.

Allow 2 weeks for delivery.
**
The questions:****

  1. Which of the following item is not a general rule for laying out stairs? **

A. The sum of two risers is always the same.
B. The sum of one riser and one tread should be between 17 and 18 inches.
C. The number of treads and risers is always the same.
D. The product obtained by multiplying one riser height by the tread width should be between 7.0 and 7.5 inches.

**
2. What should be placed on top of a concrete foundation wall to isolate the bottom plate from the concrete? **

A. Sill gasket.
B. Filler strip.
C. Continuous bead of caulking.
D. 25 mm (1") of rigid insulation.**

  1. What defines the stringer for a circular stair? **

A. The slope of both stringers are the same.
B. The slope of the outside stringer is greater than the slope of the inside stringer.
C. The slope and run of both stringers are the same.
D. The slope of the inside stringer is greater than the slope of the outside stringer.
**
4. When installing scissor trusses how should they be attached to the exterior bearing wall? **
A. Installing hurricane clips.
B. Nail down thru the top chord with galvanized nails.
C. Installing a dedicated scissor truss hanger.
D. Toe-nailing to the top plate on both sides of the truss.

Good Luck inspectors!

2

d, a, b, d

3

D
a
d
a

4

d, a, b, c

5

D
a
d
c

6

D,a, b,a

7

B
a
b
d

8

Congratulations Marcel!

  1. Which of the following item is not a general rule for laying out stairs?

A. The sum of two risers is always the same.
B. The sum of one riser and one tread should be between 17 and 18 inches.
C. The number of treads and risers is always the same.
D. The product obtained by multiplying one riser height by the tread width should be between 7.0 and 7.5 inches. C/D
**
Everyone missed this but it should have been C&D.**
D. answer had a typo and and should have read (The product obtained by multiplying one riser height by the tread width should be between 70 and 75 inches.) This would make D true to a rule.
C. because (The number of steps in a set of stairs is always the number of risers, not the number of treads.)

  1. What should be placed on top of a concrete foundation wall to isolate the bottom plate from the concrete?

A. Sill gasket. A
B. Filler strip.
C. Continuous bead of caulking.
D. 25 mm (1") of rigid insulation.

  1. What defines the stringer for a circular stair?

A. The slope of both stringers are the same.
B. The slope of the outside stringer is greater than the slope of the inside stringer.** B**
C. The slope and run of both stringers are the same.
D. The slope of the inside stringer is greater than the slope of the outside stringer.

  1. When installing scissor trusses how should they be attached to the exterior bearing wall?
    A. Installing hurricane clips.
    B. Nail down thru the top chord with galvanized nails.
    C. Installing a dedicated scissor truss hanger.
    D. Toe-nailing to the top plate on both sides of the truss. D

All questions came from the Canadian Red Seal Carpentry test. My teacher was a Red Seal Carpenter.

9

Congratulations Marcel, well done. :slight_smile:

10

Great well done Marcel

11

Marcel, are you a Red Seal guy?

12

Finally, I thought I was losing it…

Can the books be delivered to a colleague instead because I just got 500 delivered with my logo.

His name is Barry Relf and he is a interNACHI member.

Thanks!

13

I am a Red Seal guy but not a carpenter. 3 nails are required toenailed to the top plate as per the National Building Code to fasten trusses.

14

Yessir!
Glad you won :wink:

15

I give up on these questions. There has to be a broader consensus on a correct answer other than a local reference. Just toenailing a scissor truss would never fly in Florida :cool:. And, would you mind explaining question 3 for me, because that answer makes no sense at all?

16

On the truss answer, according to the code you toe nail, then you add clips if required in your area. Florida is different as well as Texas but the proper fastener technique is to toe nail first. Add all the strapping you want after.

On the circular stair question?

Pretend that you are building a straight stair stringer. Using total rise and run you would use Pythagoras to find the length . The rise over run is the tangent value which is your angle.
For the spiral the rise stays the same however the run changes. If you know the diameter of say your kick plate or stringer and the total angular turn from bottom to top you can calculate the circumference of one turn (360 degrees) or any part of the circle. That is your run.
You can now unwind that spiral in your mind and find tangent value giving you the angle and length using Pythagoras.
The outer stringer is the greater run.

Here are the steps for rise & run.

For this example the rise is 108”, 15 risers @ 7 3/16” , 14 treads
The inside radius is 40”
The stair is 42” wide.
The stringers are 2 ½” wide.

Single point curved stair layout-

Obtain total rise of stair.

Find the radius of the stair-
It may be given to you or you may need to determine it based on the size of the room.

Find the degree of the stair-
The tread depth at walk line (12” from inside face of inside stringer) must be at least 10”, in most areas.

40” + 2 ½” + 12”= 54 ½”

54.52pi= 342.4336” That is the total length of the circumference of a 54 ½” circle.
For 14 treads we need 140” of the length of that circle. 140/342.4336= .4088 of a circle, 360x.4088= 147.18°

Knowing the % of a circle which the stair runs permits finding the length of the treads at both stingers.

Inside stringer-
40” + 2 ½”= 42 ½” x 2x pi x .4088= 109 3/16”, this is the total length of run in plan view.

Take 109 3/16” and divide by the 14 treads= 7 13/16”. Enter that as the RUN and 7 3/16” as the RISE and the pitch is 42.67 and the diagonal length is 10 5/8”.

10 5/8 x 14= 148 7/16”, this is the length of the stringer. To check that enter 148 7/16” as DIAG and 42.66 as PITCH and the value for the RUN value is 109 3/16”.

Take a framing square set the stops at 7 3/16” and 7 13/16” and mark off every 10 5/8” using the calculator to produce a string of values.

Outside stringer-
Inside face of outside stringer 79 ½”

(79.5x 2 x pi x .4088)= 204 3/16” divide 14= 14 9/16” per tread.

Enter 14 9/16” as RUN, 7 3/16” RISE then PITCH is 26.23 and DIAG is 16 ¼” . Multiply 16 ¼” x 14 for length of stringer= 227 5/8”

227 5/8” as DIAG, 26.23 as PITCH= 204 3/16” as RUN

Just questions to get us thinking.

17

Brad,

You’re right that there has to be a broader consensus on a correct answer other than local reference.

Hurricane straps may be required in Florida but may not be required elsewhere…

18

Lol, I have no idea what you just said. Take a look at this spiral and tell me that the outer stringer is sloped higher than the inside stringer. Just bustin your …'s.

spiral staircase.jpg
spiral staircase.jpg600×899 121 KB

spiral staircase.jpg
spiral staircase.jpg600×899 121 KB

spiral staircase.jpg
spiral staircase.jpg600×899 121 KB

19

Cool stairs!

20

Longer run.
Here it is in English.

On a spiral the inside of the thread is 6"
The outside of the thread (where you put your feet) is 14"
Takes more stringer to support the wider part of the thread on a spiral.

As far as busting my b’s? You don’t hear me complaining do ya? :wink: