# Attach floor trusses to a block wall



## bnentrup (May 21, 2009)

FYI: I started another thread about masonry basics, but want to open a new thread specific to this question.

Background: I am looking into a complete block home (using 4x16x12 quik brick) - 2 stories with basement, and about 28'x40' home structure. I am using 20" deep floor trusses (actually very affordable) to clearspan the 28' floors.

I have been looking as to how to safely/effectively connect my floor trusses to a block wall. I know that in theory, you can attach a ledger to a block wall (grout filled solid preferably) using anchors. I am sure it has been done many times, but I want to find another option.

'POCKETS' - similar to how beams are placed in block walls, I am considering an option to place my floor trusses in the block walls. 
-Will use 'top chord bearing floor truss which have a 'lip' on the top of the floor truss that would typically connect on the top of a steel beam. 
-this 'lip' will/can be about 4" into the block, and is composed of a 2x4 sized material.. therefore, can effectively be inserted into the block wall cavity. In essence the pocket can be 4" wide x 4"deep x 2" tall. 
-my floor trusses are 2x4 stock and will be 20" deep (per the manufacturer I am using)
-I could easily use sill-anchors in the top cavity of the block, and anchor these down!!! as one would do a sill plate... not sure if that is needed though since after the pocket is installed, the floor truss will not move (with decking, and additional horizontal supports etc). This may cause more problem that worth.
-I am considering the top chord bearing joists since this will minimize the pockets (which allow for a stronger wall).. Otherwise, the pocket would be 20" tall x 4" wide x 4" deep.

Can you visualize what I am trying to accomplish here? 
-what would be the appropriate way to secure these trusses in the block wall? 
-any other foreseen problems?


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## Warren (Feb 19, 2005)

This is very possible but will require the services of an engineer and/or an architect.


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## mdshunk (Mar 13, 2005)

What do you intend to use to separate the TJI's from the masonry, since they are not pressure treated, if you set them in pockets?


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## steves (Feb 8, 2007)

mdshunk said:


> What do you intend to use to separate the TJI's from the masonry, since they are not pressure treated, if you set them in pockets?


He is using top chord bearing trusses not tji's.
you can get them with PT chords.

I would go with a ledger and hangers tho, you can either anchor the ledger as you describe or have the masons let it into the wall.

I can see keeping the height of the pockets even, a big problem.

Are the block walls finish? If not can you use a 2x4 bearing wall.


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## neolitic (Apr 20, 2006)

There are fire code issues with
joist pockets in masonry walls
as well.


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## bnentrup (May 21, 2009)

Lots of great comments-- thus the desire to post..

IF: I build the pockets, I could create a box of pressure treated material as a surround to keep the portion of the untreated top chord from touching masonry. Or, as another stated, request the top chords being pressure treated.

IF: I would do a ledger, and have them 'let-in' the ledger within the masonry... I would still need to anchor those (unless they were substantially set into the masonry) wouldn't I? Still having the problem of finding good anchors.

IF: I would use a surface ledger on the block, what are the best bang for the buck anchor systems out there? Should I use joist hangers (keep in mind that these are 20" trusses!!!) -- I need to check with the engineer of the truss manufacturer to see if they suggest face nailing the trusses to a ledger board as a method of hanging. I am sure there is a style of truss that is designed for that style application.

Therefore, as it stands now.. the consensus seems to be using a standard 'anchored' ledger to the block wall: again, I will solid fill those block that have the anchors in them all around the perimeter. I am familiar with this installation being that I have built many decks this way. However, I just want to be sure that this is a long-term solution that i will not regret! 

as far as the question about using a 2x4 bearing wall... the answer is no: We want the exposed masonry on the interior (until my wife gets tired of the look!!!) - therefore, I do not plan on having the interior walls covered at this point.

ONE LAST CONCEPT: What about the top chord attached to a 2x10 or 2x12 (not a full 20" as described earlier) attached ledger?. I just would need enough ledger to support the top chord only as I see now. Obviously, the bottom of the top chord would be out from the wall a bit, below the ledger. The top of the top chord would be fastened vertically to the ledger, and keep from needing hangers. If the manufacturer requires anything thicker than 1 1/2" of lap, then I would have to double the thickness of that ledger.

Thanks again for the good brainstorming! I am still not ruling out the pocket concept, as I have seen other manufacturers describe similar applications:


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## tkle (Apr 15, 2006)

The pockets sound like a lot more work than using the hangers. You may also end up with a dry rot problem as well as the wood swelling and popping the block. I live in a block(4 highs) with 50% windows in my main rooms. The house was built in the 50's. I would never meet the required R value of today.


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## bnentrup (May 21, 2009)

As far as the insulation factor is concerned, I am wanting to look into vermiculite since it has a 2.0+ r factor per inch. I can probably get 9" average on a 12" block = 18.0 R value plus the 1.0 r value of the block itself. I realize there will be areas such as where the joists attach that will need added insulation since they will be 'bond-beams' and a much lower R-value. This is where heat will escape if I do not insulate the 'band-boxes' well.

Now, I just found a GREAT document provided by the US DEPARTMENT OF HOUSING called Concrete Masonry Homes Recommended Practices. It details a TON including the best practices for attaching a floor truss. There are 2-best methods 1.) the pocket method!!! with a moisture barrier and 2.) the Ledger method...the number #2 (ledger) method is what they promote as the better solution due to more strength in the wall -- but they show basically a foundation anchor/sill plate anchor that is installed in a grouted block horizontally, and having threads on the outside of the block. Do you know if this is a method to consider? I am a bit hesitant on the epoxy systems which i hear can cost $40 per hole! ouch! 

Therefore, another theory to state/try in this forum.
1.) will grout 3 rows of the 4" block, drilling 3 holes over 3 courses of block, installing the sill anchors while grout is wet. This should bond the sill bolts with the grout to the block, and then allowing the thread to extend and secure to a 2x12" treated? ledger board-and bolt securely to the wall. I should then proceed with joist hangers per my truss manufacturer recommendation.


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## dakzaag (Jan 6, 2009)

> Now, I just found a GREAT document provided by the US DEPARTMENT OF HOUSING called Concrete Masonry Homes Recommended Practices. It details a TON including the best practices for attaching a floor truss. There are 2-best methods 1.) the pocket method!!! with a moisture barrier and 2.) the Ledger method...the number #2 (ledger) method is what they promote as the better solution due to more strength in the wall -- but they show basically a foundation anchor/sill plate anchor that is installed in a grouted block horizontally, and having threads on the outside of the block. Do you know if this is a method to consider?


Post the article or the link.:thumbsup:


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## rbsremodeling (Nov 12, 2007)

Frame up a bond beam with plywood, notch out for the beams and pour in place, 1/2" rebar horizontally through the beams. Strip off the forms 48 hours later


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## NJ Brickie (Jan 31, 2009)

dakzaag said:


> Post the article or the link.:thumbsup:



I already did for him on his last post. Your welcome by the way.


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## bnentrup (May 21, 2009)

dakzag: I tried posting the URL: looks like that I cannot load an url since I have not posted enough??

without the direct link (copy and paste) here it is:

toolbase.org/Design-Construction-Guides/Roofs/Concrete-Masonry-Homes-Recommended-Practices


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## neolitic (Apr 20, 2006)

NJ Brickie said:


> I already did for him on his last post. Your welcome by the way.





bnentrup said:


> dakzag: I tried posting the URL: looks like that I cannot load an url since I have not posted enough??
> 
> without the direct link (copy and paste) here it is:
> 
> toolbase.org/Design-Construction-Guides/Roofs/Concrete-Masonry-Homes-Recommended-Practices


http://www.contractortalk.com/f48/switching-gears-masonry-full-house-59802/

This is why double posts
are annoying.

http://www.toolbase.org/Design-Cons.../Concrete-Masonry-Homes-Recommended-Practices


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## NJ Brickie (Jan 31, 2009)

Slightly different article bnentrup posted, but it is written from info from the article I posted. The article he posted is more in depth with more pictures.


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## cleveman (Dec 28, 2007)

Corbel course?


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## naptown CR (Feb 20, 2009)

How about 12" block for bsement, 10" block for first floor walls and 8" for second floor walls leaves you a 2" ledge at each floor level for bearing and you don't have to worry abolut fire cuts on the trusses


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## cleveman (Dec 28, 2007)

now we're cooking with gas


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## neolitic (Apr 20, 2006)

OP said he lives near me.
Concrete block house may
make sense in Florida. 
Not so much in this climate, 
unless there is a substantial amount 
of foam insulation on the outside
of the block.
I'd be surprised if the vermiculite
core deal yielded more than
a net R-7 or 8.
JMO


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## tkle (Apr 15, 2006)

http://www.omniblock.com/


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## neolitic (Apr 20, 2006)

tkle said:


> http://www.omniblock.com/


But this is what he's
talking about?
http://www.bendindustries.com/quik_technical.htm


Besides......

_"OMNI BLOCK.....
OMNI BLOCK has been specified in the construction of over 800 structures since 1993 .......
Tom Norris Homes (of Scottsdale AZ) .....
OMNI BLOCK now has representation in the state of Florida. If you are building in the southeast region please feel free to contact Ed Weinmann.....
OMNI BLOCK is in the final stage of negotiations with a leading block plant in Cabo San Lucas......."_

Don't see much about
below zero heating senarios.


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