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Building Confidence

Volume 8 Issue 10
ISSN 1923-7162

Welcome to Dave's Shop Talk's Home Improvement Newsletter of questions from our members and Dave's answers, as well as a Tip of the Month and a Home Improvement Article, both from our website at

What's Happening

Since we are still behind with our Newsletters and this is coming out in January of 2011 (I know it is shameful!) please accept our warm wishes for the past holiday season of Christmas and Hanukkah and the very best to you and your family in the new year of 2011. We are slowly catching up with the Newsletters so hang in there. Hopefully, we will be on target by the middle of February.

Tip of the Month

When drilling through a finished frame, as when installing door pulls, hold a scrap block of plywood on the inside to prevent the drill from chipping the wood as it goes through the other side. (For more info see my article: Cabinets 1: Frameless Kitchen Cabinets at )

Ask Dave!

Last month, I answered a question on a 3-way switch which needed some correction. Please refer to the first question in the September 2010 Newsletter and the revised answer. Thanks to our member, Terry for taking the time to send his explanation of how a 3 way switch operates.

Let's get right to the questions for October:

Hi Dave, like the site. Question---I want to apply wood shingles (singular) to outside of new home. How much wood to the weather -- --and with waterproofing (black paper) what about the vertical 1/2 X1 1/2 and do I go over these with horizontal strips to fasten shingles .....Hope you can understand the question.

The wood to the weather, exposure, depends on the grade and length of the shingle. Exposure shown below is for wall applications:

Grade 1:

Length of shingle 16" exposure is 7"
Length of shingle 18" exposure is 8"
Length of shingle 24" exposure is 10 1/2"

Grade 2:

Length of shingle 16" exposure is 6"
Length of shingle 18" exposure is 7"
Length of shingle 24" exposure is 9"

The exposure should be shown on the package label for the particular grade and length.

I don't understand what you mean by “1/2 x 1 1/2”.

You strap the wall first with 1x3 or 1x4 at the exposure centers so the nails are hidden by the course above it.

Hope this helps,


Hi Dave: having a real mental block today! I'm building the 12' Octagon Gazebo. I changed the pitch from a 5 in 12 to a 8 in 12 with a center 4x4 hub cut to 8 sides. I have my 8 hips in place and they are fine. Now I can't seem to work out the blocking angles, lengths, etc. and thus the common rafters. Can you help me out on this? thanks Rick

Hi Rick,

Sure, I'd be happy to help out.

The hip rafter plumb angle for a pitch of 8/12 is 8 and 17. The plumb cut for a common rafter for a pitch of 8/12 is 8 and 12 on the square. This is equivalent to an angle of 33.75 degrees on a cutoff saw. This is found in our Rafter Tables:

What I would do in your case is to figure the approximate length of the common rafter. You don't need support between the hip rafters until they are about 24" apart. So, measure from the outside wall line to the point where the hips spread out over 24". Then cut your common rafters approximately to this length. Install the common rafters with a temporary plywood cleat across the top end of the rafter, tacked into the hip on each side, to keep them in place and nailed into position at the wall line. Then cut your cross pieces to length, square on both ends, and nail then into position against the plumb cut end of the common rafter. To get the side cut angle of the cross pieces, just lay the board across the hips, square with the center line and scribe the length and angle. The face of these cross pieces should be plumb, to match up with the plumb cut of the common rafter.

Hope this helps,


Hi Dave; I can't believe it but I cut the 8 hips at 8/12 instead of 8/17. Do I have to remove and redo or continue on with your recommendations. Rick

Hi Rick,

You got me thinking on this one.

Your hips are not a true hip rafter, as in a standard hip roof coming off on a 45 degree. These hips come off on a 22 1/2 degree, so the plumb cut should be somewhere between the two. Best to try the fit before cutting it on my say-so. I'll have to make up a scale model and figure this out for an octagon. How do the hips fit, now?


Hi Dave, I am new to the forum, so far its great. Any relation to Super Dave? :-) I am wanting to build a patio cover, approx 30'x 12'. the fascia board is not too high and would not be enough clearance to extend out 12 feet and have it slope for rain/snow. (this is in eastern Oklahoma) The gutter runs along that side of house. I have read that its possible to use a "roof mount ledger" that would attach to the roof, (maybe a foot or so behind/above gutter) or to bracket on roof, and then hang the joists on that, and support with posts on other side. I would get might height that way for sure. Is this something that could/should be done? I don't really want to tear into roof to expose the truss ends. Or any other thoughts? thanks, john

Hi John and welcome. This is not really a forum, since I'm the only guy to respond to your question.

No, I'm not related to Super Dave Osborne, thankfully. I think he stole my name, I had it before him. I get that a lot!! My son-in-law, Mario and I do the Super thing back and forth.

For a 12' span you need about 36" of height to get a 3 and 12 roof pitch, normal for shingles or metal roof. The truss ends probably would not be high enough to get good head room, as well as enough roof slope. You could run the slope of the patio cover roof 90° to the house, like a gable roof. This will cause you to go up your existing roof and tear off the shingles.

Here is a drawing:

Drawing showing how a sunroom can connect to a simple roof house with a gable roof.

When finished, your patio roof (sunroom in the drawing) would look like it was always part of the house.

Drawing showing how to extend an existing roof of a house by changing its pitch.

This drawing shows a lean-to roof supported on the existing house roof. It is the easier of the two to construct. You would have to decide how far up the roof you need to go to get enough slope.

I'll let you mull these two ideas over before going any further.


Feature Article of the Month

Remodeling 2: Moisture and Humidity Problems in the Home

Your home's worst enemies are dampness, high humidity and lack of ventilation. I live on the West coast of British Columbia, the banana belt of Canada, or so we boast. With the warmest winter climate in Canada comes the problem of moisture infiltrating our homes. Don't despair, however, for every home improvement problem has a solution. In this article, I'll discuss ways in which the average homeowner can attend to moisture and humidity problems in the home, without spending a fortune.

When it's time for an exterior paint job, take a close look at the caulking around the house. Places like the wood trim around windows and doors, on corner board joints where they form a 90 degree corner and around vents. Anywhere you notice a joint opening up, caulk it up.

Some good home improvement news is the types of caulking the industry has developed over the past few years. My choice is an acrylic latex caulking with silicon added for adhesion. These caulks are paintable and come in various colours as well as clear. Remember, they can be painted, and should be painted for added protection.

Caulking, for those not familiar with this operation, is applied with a gun, pushed into the joint and smoothed with your finger. Use a damp rag for clean up and keep your finger wet. Pick a warm day without chance of showers for 24 hours.

Now that you have secured the envelope of your house with caulking, let's go inside and see how many home improvement problems we can solve. Let's start with the kitchen and bathrooms, the highest humidity areas in the house. How many cooks in the household actually take the effort to turn the range hood fan on while cooking? I cannot emphasize enough the importance of turning that switch on when using the stove or oven. If you noticed a hole in the side of your house where the rain could run in, wouldn't you close it up? Moisture enters your kitchen, if you don't turn the fan on, where does it go? Look on the inside of the windows, that water's from moisture inside the home condensing on the cool window surface. It may be coming through the exterior envelope, through the windows or other places. We'll discuss these later, but most of it is probably coming from moisture created inside your home... read more at

Almost the End

Dan and I hope that this newsletter has been useful to answering some of your questions on home improvement. Remember, as a member of, you can research many articles on construction jobs, as well as getting individual support with your projects, from myself.

All the best for 2011!


(Ask Dave) (About Dave)

Your source for building tips, woodworking & furniture plans, house plans and building advice directly from Dave...

Hi, I'm Dave Osborne. With over 50 years experience as a journeyman carpenter, foreman and contractor in heavy construction I enjoyed working with apprentices and sharing the tricks of the trade that others shared with me. Now I get emails from Members all over the world and we include many of my answers in our Free Monthly Newsletters. Some of my answers include drawings and instructions specific to a project, but may also answer your questions. I use correct construction terminology, so you can confidently inform your building supply dealers or contractors exactly what you need.


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