CMU block wall for two story house?

[rerod]

How should a cmu block wall be built when supporting a second story in snow country? Does a floor truss ledger board get bolted to the wall like when building with ICF?

Would using concrete H blocks help with wall strength when filled with concrete? Or by installing bond beams more often?

Can someone explain clean outs, and when they are needed?

Is installing conduit inside a block wall a big deal when using a stucco finish inside?

Thanks!

 

[WNYflyer]

How should a cmu block wall be built when supporting a second story in snow country? Does a floor truss ledger board get bolted to the wall like when building with ICF?

Would using concrete H blocks help with wall strength when filled with concrete? Or by installing bond beams more often?

Can someone explain clean outs, and when they are needed?

Is installing conduit inside a block wall a big deal when using a stucco finish inside?

Thanks!

Of course everything should get laid out and designed by a competent person, but that being said.........

https://www.huduser.gov/portal/publications/PDF/conrpt_full.pdf

Also you can look at NCMA TEK Notes for a lot of guidance on all kinds of stuff. TEK Note 03-02A touches on clean-outs for grouted walls

http://www.ncma-br.org/e-tek-nbs.asp

 

[larry4406]

Of course everything should get laid out and designed by a competent person, but that being said.........

https://www.huduser.gov/portal/publications/PDF/conrpt_full.pdf

Also you can look at NCMA TEK Notes for a lot of guidance on all kinds of stuff. TEK Note 03-02A touches on clean-outs for grouted walls

http://www.ncma-br.org/e-tek-nbs.asp

Thanks for those links!

 

[rerod]

Of course everything should get laid out and designed by a competent person, but that being said.........

https://www.huduser.gov/portal/publications/PDF/conrpt_full.pdf

Also you can look at NCMA TEK Notes for a lot of guidance on all kinds of stuff. TEK Note 03-02A touches on clean-outs for grouted walls

http://www.ncma-br.org/e-tek-nbs.asp

Yeah, thanks for all that info WNYflyer.. Second story's and more described in detail..

My bud who's a union mason was trying to talk me into a block basement, but I resisted because block basements dont have the best reputation around here.. My mom spent allot of money controlling water in her block basement. But he never mentioned anything about grouting reinforced H blocks, or new water proofing methods and dimple mats. And I hadn't learned about the benefits of thermal mass and how tornado alley has grown and swallowed up Iowa.

I also like CMU's ability to act as thermal mass if 5" of insulation is installed on the outside. Ive read thermal mass can save more than 15% on your energy bills if your climate has wide daily swings like in the desert, but probably not so much with the more steady temperatures of Iowa. But thermal mass cant hurt, unless it has contact with the soil..

So, if I did move forward with a CMU house, I think I would need to insulate everything including the footings. Yet Ive never seen or read about insulated footings, so that's another question I have..

Can you install rock wool insulation under a 30" wide footing with two stories of cmu wall on top, or is that to much weight?

Thanks!

 

[WNYflyer]

Not an expert on the residential building code, but assuming the basement is designed and built according to your local residential building code which is probably the International Residential Building Code with some local specific differences. If you go with a CMU (concrete masonry unit) wall then depending or your depth of basement relative to outside grade, soils types and most importantly "Seismic Design Category" you may be forced into vertically reinforcing a CMU basement wall or even a concrete wall. I would hope your local building official would be able to help with defining those design criteria.

At my home location we have a lot of clay which swells and contracts with the seasons due to the change in moisture and some locals have had tremendous problems with both un-reinforced CMU and concrete basement walls. I don't doubt some of our local cities & towns will not allow a un-reinforced wall to be built regardless of what the state code says. Most new homes in my immediate area look like they go with reinforced concrete basement walls these days.
Now go 5 miles away to my uncles house which is pretty close to a stone quarry so his property drains so fast due to the the soil type. His 8' deep? basement walls are un-reinforced CMU built in say 1975 and the walls look they were just built and no bowing/movement and none of that seeping/staining at the base of the wall from water pooling at the base of the wall due to poor drainage.

Needless to say how well the different types of basement wall construction perform in the long term can be very location specific.

As far as insulation is concerned around here for new basement walls it seems like they use plastic/vinyl backed bat insulation attached to the interior of the basement wall for the full height, I am assuming that is code. I see no reason why a normal basement wall footing would get insulation under it, plus they all would probably compress.

Link to residential building codes but since it is free it is a pain to navigate. Different states show up on the left.

https://up.codes/codes/new_york

 

[rerod]

No codes or inspections in my county, but I did mention I would reinforce and use bond beams and concrete grout. I'm thinking 10"x30" insulated footings, 12" block basement, 8" block to the second floor poured solid. H block creates a bond beam every course.

If you want to successfully use your cmu wall as thermal mass it needs to be insulated from the 50 degree heat sink soil. And the extra cost to insulate the footings, plus also prevent them from wicking water would be worth it imo.

 

[WNYflyer]

No codes or inspections in my county, but I did mention I would reinforce and use bond beams and concrete grout. I'm thinking 10"x30" insulated footings, 12" block basement, 8" block to the second floor poured solid. H block creates a bond beam every course.

If you want to successfully use your cmu wall as thermal mass it needs to be insulated from the 50 degree heat sink soil. And the extra cost to insulate the footings, plus also prevent them from wicking water would be worth it imo.

If you are going to reinforce the cmu then you can use the linked code as guidance for code minimums. Probably assume the worst soil type and Seismic Design Category.

Thanks for those links!

Your welcome, The TEK-Notes really do a good job of giving an idea of typical details as well as give in-depth explanation of some design and code requirements.

 

[3onthetree]

CMU can be used for multiple story bearing wall construction. Depending on the design, you may have pilasters and use of wider blocks, like 10" and 12", LOTS of vertical rebar and bond beams. Note that "H block" shapes were really invented to speed up labor, since they make it easier to place around rebar. Use of a "bond beam" shape would probably be designed for your situation. Also, CMU's are "grout" filled, not usually "concrete" filled. If using "concrete," a special mixture would have to be spec'd.

In terms of thermal mass and solidity of a material, CMU is the poor man's poured concrete. You can fill cells with insulation, but at some point there may be no $$ return on your cost or difficulty in using CMU for the entire house. Especially if DIY or in a rural area, the level of expertise and technique required increases as you go up stories, provide lintels, and joist/beam bearing.

Cleanouts are for inspecting and cleaning out around vertical rebar, so when it is time to grout fill, you get a clean and continuous attachment to the rebar down to the bottom. In a rural area, I assume grouting each course as you go would be acceptable to the AHJ for a small residential building.

Inbedded electrical boxes is labor intensive. If it is critical aesthetically on the interior then there's your answer. However, I would assume you would furr out the CMU walls for insulation.