Building Confidence

Volume 9 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 Happening

Well, as you can see, I didn't get a newsletter out in mid September. I think, realistically, we will continue with a newsletter once per month. Sorry, Dan. We did, however, write a new article in a newly created section: Concrete Work 1: Exposed Aggregate Driveway. Check it out at:

Tip of the Month

When building a project from wood, draw a simple sketch to make it easier to allow for thickness of materials. Ref: Remodeling 22: Remodeling Finishing Answers.

Ask Dave!

Hi Dave we are installing patio (garden) steel exterior doors on our new cottage. Double doors, with one fully opening to the outside. I have been given price quotes ranging from $488 at McDiarmid, $750 at Rona, to over $2000. What should I be looking for and what is a reasonable price? Thanks Andy

Hi Andy,

I can't comment on prices, since we live in different spots on the continent. The garden patio door, at least in my area, is a patio door set that will fit into the rough opening of a regular patio sliding door unit. It may be shorter than the standard 6'-8" door height.

Another thing to watch for is the grids. You usually have two choices: external or internal - referring to the muttin bars between the glass panes or on the outside. Obviously, the bars installed between the two panes of glass don't need cleaning and look much better, in my opinion. These are the internal bars. These are the basic differences for the standard doors. You can go for high end doors with oval glass and all the other designs.

When purchasing these doors, make sure you get the rough opening size from the salesman, if installing the rough opening before you have the doors on site, which is usually the case. Usually, both doors swing out, 180 degrees to open up the room to the outside - a nice feature. One door is considered a stationery door and the other is considered the active door, but they both should swing out.


Hi Dave what do you recommend for a vent (plastic, metal, size?) for pony walls in a crawl space foundation, and how do I install a vent in a 2x6 pony wall with studs on 16" centers, and fiberglass insulation? Do you also recommend a window ? Thanks

Hi Andy,

Vents in a crawlspace are required by the building code, unless the crawlspace acts as a warm air plenum for the furnace. Otherwise, you need vents. These are very simple, plastic vents that open and close by sliding them horizontally. They fit into a 14" space, so they don't need special framing. They should be across from each other and spread out so there is good cross ventilation. There is a simple formula which helps you know exactly the number of vents to put in a crawlspace, based on the area of the floor in the crawlspace. The vents required in a non-heated crawlspace is not less than .1 m2 for every 50 m2 of floor area. This means 1 to 500; vent area to floor area.

In your case: 33' x 24' = 792 sq.ft, you need 1.6 sq. ft of venting. This works out to about 4 vents, spaced out on the 33' walls. I would suggest coming in about 8'- 3" in from each end at the center of the vents, leaving a 16'-6" space in the middle. You don't want too many vents to freeze the pipes in the winter. You can either frame the vents or cut the insulation out on the bottom of the vents and let it just lay over the vent in the winter. In the spring, each year, fold the insulation back out of the way of the vent and slide it open from the outside. Depending on your temperatures where the cottage is, you may need to have electric heat under the pipes to keep from freezing. Get the base board that has a thermostat built in. Remember to frame in an access door.

When installing the plumbing, don't run your supply line in from the end and laying in the crawlspace. Bury it under the slab then come up right in the middle of the plumbing area. This shortens the exposed plumbing from freezing problems.

No, I don't recommend windows in a crawlspace. I feel it would be a waste of money in a 3' high crawlspace.


Thanks for all the great advice Dave. What is your recommendation for insulating under the main floor in the crawl space? I was thinking that if possible I could install insulation during the build from the top of the joists, which seems to me would be easier than installing insulation from under the floor after the sheeting is installed. Thanks Andy

Hi Andy,

Installing insulation before the sub-floor is a good idea, if it doesn't rain. Don't make the mistake of applying vapour barrier, the floor doesn't need vapour barrier. The carpet or lino becomes one. Also, put strips under the joists to hold the insulation in.

Another thought: do you really need to insulate the floor if the perimeter is insulated? Will you be using this cottage in the Winter?


Hi Dave yes we are planning to use this in the winter. I have enough tarps for the subfloor in case of rain or (yikes) snow in the next 6 weeks. Do I need to use paper back fiberglass insulation in the floor? So I don't need a vapour barrier on the crawl space side of the subfloor? Thanks

Hi Andy,

No, don't use any vapour barrier on the bottom of the joists. That is a big mistake lots of guys make. VB has to be on the warm side of the insulation or it creates condensation.


Ok great, but do I use paper backed insulation with the paper facing up? Or just regular fiberglass?

Regular fibreglass batts.


Dave I am planning on building the pony walls and then sheeting with full 4x8 treated plywood after the floor joists are in place. Do I need a vapour barrier on both sides of the insulation in the pony wall? Thanks

Hi Andy,

No, you want the vapor barrier on the inside - the warm side and breathable tarpaper - 30 or 60 minute on the outside, between the framing and the siding. You never want to enclose a wall in poly where it cannot breathe.


I thought so but as I am sure you know Dave there are many, many opinions out there, most of them unsolicited. Thanks for the guidance. Andy

Thanks, Andy, keep 'em coming! Every question you have, there is probably 100 out there wondering about the same thing, but too bashful to ask.


Hi Dave how do I build an access door/panel in the floor for crawl space access? The plans call for an opening in the floor joists, but I am not sure how to build the access door. Thanks

Hi Andy,

The crawl space access must be at least 20x28 inches. Here is a drawing of the access in a floor:

Diagram of a crawl space access in a floor showing double joist and joist hangers.

Double up the joists on each side of the opening. Frame in the opening with joist hangers to the double joist, to support the sides of the opening.


Thanks Dave - how does the double joist work with engineered floor trusses?

Hi Andy,

Engineered floor trusses is a totally different thing. You need to contact the people you bought these from and they will tell you what needs to be done. Otherwise, you lose you warranty if you start cutting these trusses.


Hi Dave for my pony walls do I need pressure treated or PWF lumber? What's the difference? Thanks Andy

Hi Andy,

PWF or permanent wood foundation is made from pressure treated dimension lumber and plywood. If the pony wall acts as a retaining wall for backfill it needs to be a PWF. If siding is attached you need the bottom plate PTW pressure treated wood, or standard lumber with a sill gasket under it.


Dave what is the nailing pattern required for laminating the LVL beam? Thanks

Hi Andy,

The nailing pattern, size and spacing of the nails, should accompany the beam in the Specification papers from the Engineer.


Hi Dave what caulking should i use between the wood pony wall bottom plate and the concrete slab? Thanks

Hi Andy,

Usually, we staple the sill gasket to the bottom of the plate. This keeps it off the concrete as well as forms a gasket between the uneven surface of the concrete and the wood. We do not need to caulk the bottom plate, if you follow these procedures. The bottom plate should be flush with the edge of the concrete slab. The siding is nailed to the bottom plate and extends below the plate, overlapping the concrete joint, so this method keeps any moisture out.


You can see that Andy has been busy the last month, or so. He writes, "we are building a new cottage on our lot at Lake Winnipeg. I have ordered a prefab. It is just over 1000 sf including a 250 sf loft. I just got the building permit after getting the foundation and structure plans engineer reviewed and approved (as required by the local RM - {authority having jurisdiction}). I am making a choice for foundation contractor. The foundation is thickened edge slab on grade, with 36" wood pony walls (for the crawl space), and an LVL (3 ply) 5-1/4x9-1/2 1.8E 33' center beam with teleposts. The prefab comes with 24' x 2 x 11-7/8" TJI engineered wood floor joists. It also comes with 4 - 12' x 11 7/8" - 2x6 end gable pony walls. I am planning to build the 2x6 PT pony walls myself. So from the end there will be concrete slab, 36" PT 2x6 pony wall, and 2x6 end gable pony wall."

Andy is going about his project the right way: using the internet for ideas, going with a pre-fab package, including proper plans, getting a building permit and getting proper engineered beams, getting a contractor for work he is not comfortable in doing himself, getting advice and asking questions.

Really simple question - is there a correct way to sharpen a carpenter's pencil?

Yes. The carpenter pencil is designed for scribing, so should be sharpened to a flat edge, rather than a round point. If we had our block planes handy, we would sharpen them on the plane. A utility knife works well, also.


Dave, I have decided to use a wood stove in my workshop, That way I can have heat and someway to burn my mistakes. I am thinking about using cement board under the stove and attach it also behind the stove against the sheetrock. What do ya think. Will that provide enough protection against fires??? I will be venting with triple-wall vent pipe on the back wall, going out the side and up to the desired height above the roof. Thanks, have a great day, Kelly in Port Orchard, WA

Happy Canadian Thanksgiving, Kelly,

This sounds good. I would add a piece of sheet metal attached to the wall with 1" or longer, spacers. This piece should be about the size of the stove. The air in the 1" or greater, space remains cool. Keep it saw dust free, when working with the fire on. Get in the habit of blowing off the dust every once and awhile.


Dave, I am putting up a wall in a building that has a metal skin. The wall will be 2 X 6 with insulation and sheetrock on the inside. Should I use plastic sheeting during this process??? I'm thinking that it might not hurt if I use a vapor barrier between the outside wall and the insulation; What do ya think?? Would it be better to use a VB between the insulation and the sheetrock??? Thanks in advance for your help. Have a great holiday weekend. Kelly in Port Orchard, WA

Hi Kelly,

No, I would not put poly on the cold side of the wall, always on the warm side - between the insulation and the drywall. No problem with a breathable tar paper, though, which keeps moisture in but lets vapor out.

Looking forward to the weekend, although every day is a long weekend when you are retired. We are having a mini family reunion at a park not too far from here so that is always good!

Later, Kelly,


Hi Dave, we are re-doing our stairs, going down stairs with solid oak thread. there are 10 threads. After they are done i was thinking of staining them Golden Oak stain that is what i have on our floors. What kind of stains should i use so it is not slippery. i was not going to put anything over them but stain.

You need to put a varnish or clear finish over the stain. The stain only changes the colour of the wood, it does not protect it. I prefer a polyurethane finish such as Flecto Varathane or Minwax.

This is the finish applied to hardwood floors. This finish may be slippery with socks on, but not that bad.


Feature Article of the Month

(taken from our website:

Remodeling 14: How to Install an Arch in an Opening

Here is a sketch that may help explain the framing detail for a rounded corner or arch:

Diagram of framing a rounded corner in an opening showing header, plywood cut to an arc and stud cripple.

Cut out the desired curve from a piece of 3/4" plywood with a jig saw, etc. You need two such pieces for each side or four for both sides.

Nail the plywood curve flush to the edge of the framing on each side of the 2x4 wall, between the header and the cripple.

Nail or screw the drywall on the face of the wall first. Cut the shape of the drywall out with a drywall saw, following the plywood edge as your guide.

Depending on the radius of the curve you can more at

Almost the End

Well, that does it for another month. We hope some of these questions and answers will help you with your own projects. If you need more advice, join our website, then send me an email.

Keep up the good work, Andy. I guess the snow is falling about now!

Thanks for your emails and support.


(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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