Building Confidence

Volume 12 Issue 10
ISSN 1923-7162

Welcome to Dave's Shop Talk's Home Improvement Newsletter of questions from our members on their construction projects, a Tip of the Month and a home remodeling article, both from our website at

What's New

Dan and I are continuing the Free Plan of the Month.

Each month our readers will have free and full access to a different set of plans on our website. Access will be limited to about a month while that Newsletter is active until the next newsletter is sent out.

Our Members (paid subscribers to our website) can view ALL of our Plans, ALL of our Articles, Tables, Jigs and Calculators at any time. Our Members not only have access to our entire site, but can also email me directly with any questions on their projects (a service available only to our paid Members).

The Free Plan section of our Newsletter is the last section just above my signature.

Tip of the Month

When installing OSB for sheathing on a house exterior wall, be sure to allow 1/8" for expansion and contraction between the sheets, all around. The inspector will be looking to see that you did. Ref: Tables 6: Nail Table.

And a Bonus Tip:

A 4 1/2"angle grinder with diamond blade works great for a homeowner cutting notches in ceramic tile. Ref: Remodeling 10: How to Lay Ceramic Tile.

Ask Dave!

Stairs: Choice of wood for treads and risers Hi Dave, First off, many thanks for your stair calculator and the whole package of stair info. I've now successfully built my first-ever stairs in the house we're building! See attached photo. While I'm very happy with these stairs, it did occur to me that my choice of fir for the tread wasn't very clever, as it won't wear well. So for the upper stairs (it's a three-floor house) I wanted to use hardwood for the treads (and probably the risers, purely for aesthetics). So, what would you recommend? I was thinking of oak, but maybe something else would be more suitable. All the best, Steve

Hi Steve,

Looking good! Actually, Douglas fir is considered a softwood, but when it dries it very much resembles a hardwood. They used to used D. fir for floors around here in the early days. Today they go more with oak, but maple is getting popular, as well. I don't know what is available there in France, but oak is a good choice for flooring. Birch, here is the lowest price and is not as open a grain as oak and can be stained to look like maple or other more exotic or expensive woods. Glad you like the Stair Calculator.



Hi Dave I have a relativity new stockade fence that I just pressure washed. What would you recommend to seal it with. I have used Thompson's Water Seal in the past but I have heard there are better products out there. What would you recommend? I want to leave it looking natural so I am not interested in staining it to change the color. Thanks Ron

Hi Ron,

My wife is a paint/stain expert having worked in that field for a number of years. She always claimed that Sikkens Cetol was the best product for decks, especially. We needed to redo our bench seats and picnic table on the back deck and she came across a CIL product which was a hybrid - latex/oil. (It is getting harder and harder to fine an alkyd oil product around, everyone seems to be going with latex.) Anyway, my wife bought the CIL Woodcare Exterior Wood Stain for Decks, Fences & Siding. She was very impressed with this hybrid product - properties of oil, but soap and water cleanup. It has a good hard protective finish. It comes in a number of colours, don't know if clear is among them, but a light natural stain is included in the choice. Might be worth a look into. I notice Cetol is putting out a hybrid product, as well.


Greetings Dave Osborne, My question is when installing barge rafters to support an overhang on a roof, using 2 x 6's, is there a standard (or recommended) spacing on how far apart to set the barge rafters. My overhang is 32", it's a 10 in 12 roof with a span of 17' plus the overhand. My rafters are on 16" centers and I'm going in three rafters due to the long overhang. Any info would be appreciated. Regards & God Bless, Bret

Hi Bret,

When framing for a gable end overhang, usually an overhang up to 16" can be done with out building "ladders" or "look outs", as we call them, for the overhang. In your situation, with a 32" overhang you should use the ladder technique as you have chosen. The rafters going out 90 degrees with the gable end usually sit on the gable end truss which is cut down by 3 1/2". The look outs then are 2x4 on edge and usually go inboard over the gable end truss into the next truss laid out on 24" centers.

In your case with 2x6 rafters, I would do the same, except as you say remove one rafter from the the gable end and attach the look outs into the second rafter over from the wall line, at least 24" from the wall line. On the wall line build your gable end rafter lower by 5 1/2" (or 3 1/2" would do, too, depending on the choice of barge boards matching the fascia). These look outs should be laid out on 24" centers starting from the eave where your sheet of plywood starts. May as well have the 4' joint of the plywood butt up on one of the lookouts. Also, the ridge board should continue and catch the overhang rafter on the top and the rafter trim catch the bottom. When installing the plywood, try to get most of the sheet on the roof to help support the overhang. Stagger the sheets here by only 16" with the longest sheet in the center of the span. That is, make sure the overhang sheet nails into a rafter at least one inboard from the lookout connection. This way, your sheathing helps support the overhang, too.

Here is a drawing to help explain, this can apply to rafters, as well:

Diagram of roof lookout showing top chord of truss, gable truss, inboard truss, truss gable trimmer, barge board, fascia board, truss trimmer and top plates.

Hope this helps,


Dear Dave, Thanks a ton for the information and drawing, that's exactly what I needed! I really appreciate your site and its' thoroughness, not to mention being able to ask you this type of question and get your expertise. Thanks again! Regards & God Bless, Bret
I need to install a couple plumbing vents for sinks I am installing and would like to run the vents horizontally through a side wall rather than through the roof. Is this OK to do? If so: 1) Do I need to install them so they tilt down a little to keep water from following the exterior of the pipe into the wall and 2) How do I terminate the pipe, with a vertical T or just cut off the pipe?

The purpose of the vent is to ensure that the p-trap is not siphoned out, it breaks the siphon with a vent. The vent will contain sewer or septic gases which smell and are flammable, that is if the sink drains to the sewer or septic tank. This is the reason they are always installed through the roof for the wind or air to disperse the gases. Try to get it up the inside of the wall and out the roof or into the attic to a reachable place then up through the roof. In the "old days" it was allowed to run the vents on the outside of the house, but still they had to be run up the roof, usually in the overhang.

It would be kind of embarrassing to have a friend walk by the vent at nose level, which would be bad enough, smoking a cigarette and poof, lose all his hair. He wouldn't be too impressed, either.

Better to do things, right.


That makes sense, thanks. One more question, does the vent have to be installed directly above the P trap, e.g. with a "T", or can it simply be close to the P trap, say within a couple inches? In one of my applications the drain runs in horizontally and ends at the trap. The way I have it installed is the drain ends in a street L connected to a T on the downstream side. The vent runs vertically off the T, so it is actually downstream from the trap. Should I change it so the vent runs off the end of the T and the trap connects in the center of the T? Also, how many sinks can be connected to the same single vent? Thanks

What you described is okay. The number of sinks for one vent depends on the size of the p-trap and vent. For a 1 1/4" p-trap and vent, only 1 sink is allowed. With a 1 1/2" p-trap and vent you can have 8 fixture units connected where a lav (bathroom sink) is 1 1/2 fixture units, so that's 5 lavs off one 1 1/2" vent. The trap can be 5' from the vent. You are allowed to use half the diameter vent as is the drain. So for a 3" drain for a toilet, you can still use a 1 1/2" vent. A toilet is considered 4 fixture units. This is just about dry vents, when you are talking about wet vents, relief and circuit vents that's different.

Hope this helps,


Feature Article of the Month

(taken from our website:

Jigs 1: Table Saw Feather Board

A feather board is a handy jig, something you can make yourself or purchase ready made.

Feather boards are used for two purposes. First to hold your work when ripping tight against the table and tight against the table saw fence. Second, they are used to prevent kickbacks when ripping small pieces, if the piece twists between the blade and the table saw fence. There are feather boards out there that you can buy that will do this very well, they either clamp on the table saw fence to hold the work tight to the table or clamp in the miter slot of the table saw to hold the work against the fence. There are other feather boards out there that actually are magnetic and hold securely anywhere on the table. That's the problem of a home made feather board, how to... Read more at Jigs 1: Table Saw Feather Board.

Almost the End

Hope you enjoy the Newsletter this month.

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(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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