Single wall top plate

Wouldn’t want to be the poor stiff hanging the s/rock. The ceiling s/rock will cover 5/8 of an inch leaving less than an inch to catch the nails or screws…

Single top plates and other labour and materials saving techniques were were combined in the 1980’s (or maybe before) to give the OVE (Optimum Value Engineering) framing system. As well as being a money saver, it improved the energy efficiency of dwelling by having more insulation and less low R value wood in the exterior walls. Other techniques were the 2 stud exterior corner, eliminating lintels (headers) over windows/doors in non-load bearing walls, and single studs along side load bearing windows and doors.

For those that are in areas where 2x6"/R20 walls are popular, the average R value of the wall can be as low as 17.2 to 18 due to the amount of framing in the wall. It can be as much as 20% in some walls; all low R value, expensive wood (1.25 R/inch) versus insulation (R 3.5 +). And more wood means more labour!

Finally Brian.
You start talking normally again…….HI or Brian…

Happy you are here. No joke.
Please excuse any jocularity. You are truly a good sport.

Energy saving design in the eighties were groundbreaking. Energy the focus but not many builders had the capability of erecting housing properly IMO.
I can see the 2/6" 24 "centers wall stud and there relationship to engineering but Kenton point hits home.
Engineering to the extreme limit as expressed in the thread is improper. We know builders will cut corners.
When you cut corners on this style of structural wood frame building you are asking for trouble.IMO
All the best Brian.

I would prefer double wall top plate but this single plate seems to do the trick. As long as there is not a ton of snow on the roof like we can get here in Quebec!

My crib work days go far back Joe. Beer was still cold and the women warm.:slight_smile:

Doubled sill plates are all I can remember and still see them using doubled sill plates on homes today.

Marc. It is not so much for dead load as it is for live loading.
yes snow is live loading but in the states and along waterfronts and open fields wind shear is amplified.
One 2/4 does not allow the manufactured hurricane plates or straps enough anchorage if my mind is working right.

like to get together and talk HI you know my number.
HI only please.
Hope you has fun in Ontario.

A single plate will not hold a truss or rafter in place when hurricane winds are loading a wall/eave or when seismic tremors are live loading the structure altogether.
I could be wrong.
I will look it up again.
Just my 2 cents.

Single plate are a call out.
I have called out 2 this year. Its a bear to crawl in an attic to the eave but when you have to, you have to. I must get photos.

PS: Mark and Joe.
The first home last year had the roof re-engineered but the builders used one 2/6" plate and walls had 2/6" with 24 centers.Doubled on loading areas.

The mechanical casement windows on the second floor jammed in the pockets. Once you got the out of the frame pocket they opened and closed with ease until the were returned into the framing pocket.
All the handles where off on all the windows on the second floor. It caught my eye. The main floor windows, all the same by the way worked great.
That sent me into the attic with a hypotheses. Loading and sill plate for one.

Agree with HI! I have a long PDF on Optimum Value Engineering and feel that new homes should be built with minimal waste. One of those wastes is 16 OC. The energy lose is also recognized as there are more points of bridging.

when we discuss waste they why use metal studs. It cost more money to make a steel stud they to plant a tree and harvest it in the same country.
Engineering tall building is shifting to wood. building as tall as 20 to 30 stories. Sorry I lost the material in April.
Wood and 2/6 with 24"OC is fine.
As for Thermal bridging. Materials at certain intersections can address bridging IMO. The same idea as window frames. A composite of mixed materials that block conductivity bridging.
What say you billy Nye the science guy if you are listening.
here is a decision and the top and bottom sill plate.

IRC 602.3.2
It is dependant upon the material used.

A single top plate is allowed under the International Residential Code (IRC), but it is an uncommon
construction practice. Standard practice for exterior and interior wall framing is to use a double top plate to.

The single top plates must be adequately tied at joints, corners, and intersecting walls by at least a*** 3-inch x 6-inch***, 0.036 inch-thick galvanized steel plate that is nailed to each wall or wall segment by six 8d nails on each wall segment. Rafters or joists bearing on a single top plate must be within ***1 inch of center over the studs below. ***
The top plate may be omitted over lintels that are similarly tied to adjacent wall sections with steel plates

I am sorry. I was using 2/4" constriction as my memory served me.
I have never built 24OC and using 2/6" material.
Sorry Joe.
I hope I did not confuse the issue.

Engineering and energy efficiency in buildings is understood.
Thermal bridging in materials is now being understood after decades of information.
That being said Kevin; I still see homes built without adequate insulation in the foundation, walls and attic space. I do not see thermal bridging in framing as being a key concern as of yet.
Once stiffer building practices take effect I can see a new approach to energy efficiency in new homes. But for now You still have a stockpile of older homes on the planet.

Here it is just being addressed in the new OBC 2006. We want all to be aware of us being on the top as to energy efficiency in building design. What I expect to see next is Value Engineering put in place on a wide basis. Say good buy to 16 OC walls and 2x4 structures.

That would be great Kevin. But that would mean only Ontario would be a player.

This will spread to a town near you Robert! Get a foot hold on the OVE installation practices and OBC 2006 so you are ready.

It all boils down to costs…

Cost of energy versus cost of construction/material.

A 2x4 exterior walls with spray foam insulation would perform better than a 2x6 exterior walls with fiberglass insulation just as a 16 in OC walls with spray foam insulation would perform better than a 24 in OC walls with fiberglass insulation.

Why bother framing at all.
Just go SIP’S or ICF.
What you save in labor you more than make up for in the cost!
Both are recognized in the OBC.

Some info from your friend on the topic at:

I thought I could a least have one day without hearing his name!
Thanks Marcel.
I almost made it.

Marcel makes a valid point Kevin. For the moment the cost of reconversion over to 2/6 24 OC building outstrip the means of conventional 2 by 4 timber framing.
#1 You have to reeducate all the framers,
#2 refit the lumber yards and #2b. import new hardware. It is not that easy to startup a program as one thinks.

99 percent of the buildings are 2/4" 16" OC like it or not.
Energy can be saved by using other ways and forms of producing energy.
Insulation and thermal bonding is just one piece to a complex puzzle.
Energy used efficiently.

Once the new window that radiate heat into a living space are developed to be more efficient and cheaper the energy cost to run homes in a Northern climate will be cheaper.

Looking for a building made of ICS a couple of blocks away Marcel.
I wanted to gain entry to see how the tie in the flooring and roofing system.
great artical.


I am looking for some insight regarding a potential new construction home purchase - hoping to get expertise and perspective from experienced folks on this forum.

Some background … I am a first-time homebuyer and not in the construction industry - thus I have relatively little understanding of structural practices or lingo. I am trying to get an understanding of the risk involved and ultimately whether I should “walk away” from this particular home/sub-division.

The builder is Richmond American Homes, a large national builder. The specific project is located near Seattle (seismic risks). I noticed that the builder has a number of complaints posted from angry buyers online (BBB and dept of consumer affairs websites) about construction quality issues, including some that would be considered “major.” For example, cracking foundation resulting in basement floods, major visible cracking of interior walls, leaky roofs, etc. However, given that it is a large national builder, I don’t have a good feel for what % of the homes these ~60 complaints (over the past 5 years) really represents.

The sub-division I am interested in is currently in the early stages of construction. I just went to the site and the City inspector was there. So I picked his brain and here is what I learned:

He said the construction was following plans and meeting minimum code. He didn’t express concern over the quality of the sub-contractors work, but did express some hesitation about the quality of the design they were building to.

  • Two-story stick-built house. 2,000 sqft.

  • Framing: 24" center on stud, with a single top plate.

  • Main floor has Joist supports. Second Floor has truss supports.

  • Foundation: Crawl space design. Footers with foundation walls.

Foundation walls are 4" thick and vertical re-bar is spaced 4 feet apart. (he said this was pretty far relative to what he normally sees)

  • Foundation interior uses walls rather than posts with support footers.

The inspector said that although it meets code, he feels that the combination of “light framing”, “sparse rebar”, and use of a single top plate all point to a fairly “cheap design.” He didn’t seem confident that it could withhold a 6.8-earthquake.

Given this impression, and the fact that this is a larger national “production” builder (profit over quality), and the seismic risks, does this sound like trouble in the making? What sort of risks would be incurred/exacerbated by use of the the design features described above?

I’m struggling with the fact that it meets local code, and I would think/hope that code has a decent “margin of safety” built into it to ensure that the structural integrity is not compromised.

Some perspective is appreciated. What would you all do? Are there any other questions on design I should ask the inspector to help arrive at an answer?

I would appreciate help!


Code is code.
If you wish to build with the builder than modify any plans he has and absorb the cost over-run.
just insure that the key areas of concern that transfer load are over built.
Just my 2 cents.

I still scratch my head seeing every contractor do it the old way. It is almost ingrained to go to the minimum with the building code.