Home With 2x4 Walls

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Posted by: from Laclabiche
2/23/2013 at 1:42:14 PM


My son just bought a home that needs extensive reno's. It has 2x4 walls, a gable end that we want extended six or eight feet, new kitchen, new bathroom, panelled walls removed and drywalled, and ceiling redone.

How big of an issue is the walls? Should we upgrade to equal 2x6 walls from the inside or just renovate and not worry about the r factor?

It is a 1978 home with concrete basement that has no interior walls. This is a major project for sure and need to know what steps to take.

Thank you for your time in this matter.


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Date/Time2/23/2013 at 3:27:06 PM

This is not our area of expertise, however on a personal note I would definitely build out the walls from the inside to achieve maximum R value. This would also allow you an opportunity to do all necessary electrical upgrades, etc.

Good luck and be safe.

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Date/Time2/23/2013 at 6:10:52 PM


It would definately be in you best interest to increase the wall thickness. Simply put, 2x4 walls ... of that vintage, ... usually have a R factor of R7 ... mayby R 12. The higher the R factor the better. A 2x6 wall, in today's market, has an R22 rating (depending on the insulation). That would be the first step.

Next, I would look inside the attic to see how much insulation is there. Again, in todays building codes, the recommendation is to have R40 - R50 in the attic.

After that, decide on the other items such as size of kitchen, layout, access, lighting, etc., ./.. and the same with the bathroom. I would suggest making a budget, if you haven't already done so, and decide on priorities. Might I also suggest not to go too cheap on the items you'll require (sinks, toilet, tubs. lighting, flooring. etc.) because, quality stands up better and if you are to re-sell in the future, all the improvements are a selling feature.

Back to the walls for a minute, the new walls would provide much better heat retention and payback (the amount of time it would take to recover the cost) is usually about five years. This is the savings in heat bills and from that point on, it's a bonus.

I hope this helps.



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Jeff from Newson Interiors in Dunrobin
Date/Time2/23/2013 at 6:26:13 PM

Hi Darlene,

Sounds like your son has a big project on his hands. This is the perfect time to address the insulation issues with the home. Before going ahead and beefing up the walls to accomodate conventional batt insulation, consider pricing out spray foam insulation. Before condmning the cost consider the cost of the 2x2 lumber, and vapour barrier, which wont be needed. 5.5" fibreglass about r 19 (perfectly installed-no air gaps) 3.5"closed cell foam r21 with no chance of air gaps. (If installed properly.)

Be sure that all wiring is installed, and inspected before spraying.

Hope that helps.


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Date/Time2/23/2013 at 6:51:51 PM

Hi Darlene,

There are ways to make the walls more efficient with a proper building envelope. It's not just about energy costs, it's about comfort. My first house had 2x4 construction and it didn't matter how much you cranked up the heat it will escape just as fast as you pump it in.

We specialize in getting the most out of the space in style.

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John from JALS Corporation in Welland
Date/Time2/24/2013 at 9:01:00 AM


If you are removing the panel sheets anyway I would suggest strpping all the wall studs with 2x2 install all the new wiring and then insulate with R22 (code) or price out spray foam with the foam you will not require vapour barrier. Get the attic insulation up to code.

If you thinking about replacing the windows do it before you insulate.

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MOJ Contracting in Aurora
Date/Time2/24/2013 at 9:53:54 AM


As some have said, if you are considering upgrading your insulation, I would suggest using 2x4 walls with spray foam insulation. New research has proven that "less" spray foam insulation works better than regular batt insulation. The Rvalue is somewhat irrelevant. In colder climates foam works way better than batt insulation in stopping air infiltration. Costs are a little more to start, but long term the savings and comfort will be a benefit you will be happy with.

One thing to be aware of, if you do make an airtight home you will probably need some sort of air exchanger or heat recovery unit to ensure indoor air quality is good all year round.

Good luck with your reno


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Mike from NEVE Groupe Construction in Mansonville
Date/Time2/24/2013 at 12:10:11 PM

Looks like a big project, would suggest getting an architect and engineering plan done to prevent any structure surprises down the road.

Wrt the 2x4 walls, you can simply have a team spray foam to simultaneously achieve @R 21 and vapour barrier (with 3" of foam). With his you will have to ensure the attic is properly insulated and sealed at the same time.

Hope this helps.


NEVE Construction

819 239 1894

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Date/Time2/24/2013 at 8:48:33 PM

Hi Darlene,

Sounds like you have some fun planned for your future.

Your scope of work makes it seem like you are gutting the place any way so you should definitely take the time to upgrade the structure and add insulation. If you can go with closed cell spray foam, that would be the tightest and give you the highest R Value. If that turns out to be cost prohibitive, I would go with Roxul - good R value, doesn't support mold, and pretty critter resistant.

Think of it this way - you buy insulation once and you buy heating and cooling every day! Might as well do the best you can when you have the chance!

Good luck with your project!

Jim Kuzma

Kettleby Handyman Services

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Date/Time2/26/2013 at 1:55:58 PM


There is no need to upgrade the 2 X 6 walls. They should be left alone. As for the renovation-addition, all those new parts would be done by code with 2 X 6 walls and an appropriate insulation factor.

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Shannon from Panoramik Design Build in Ottawa
Date/Time2/26/2013 at 11:05:21 PM

Some good information and opinions given. But it is just that.

You will need to go to your city and find out what they want you to do. Also contact the city and get the list of things needed to obtain a building permit.

What I would do is hire an engineer and get drawings done. They will know what the rules are and will be able to get your project started quickly. Most often the cities will not allow you to do a major project like this unless you have stamped engineer drawings.

Make sure that all the information is given to the city and your project will run smoothly.

Good luck

Jeff Picard

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