Wall detail - best design with conditioned crawlspace and hung joists


dnh234589
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Nice job.

 

For details I like solid arrowheads, and all my arrowheads are slightly smaller than my text size.  That goes for plan views and elevations, too.  

 

Examples:  All my 1/4 scale anno and dimension text is 4.5 inches tall, and all my arrows are 4.  Details at 1" scale get 1.25 inch characters and 1 inch arrows.

 

You might want the look of curved arrows instead of doing the angle break.  To curve the line, start the arrow by dragging in the direction and then hold ALT and watch what happens.  The ALT key held down enables you to curve an arrow already placed, so if I am doing curved leaders, I draw the arrows all first in the direction I want from the anno text, then go in and arrow by arrow use the ALT key and drag the arrowhead to the object or surface I want.

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Looks good. I have a few questions regarding the placement of:

1. the sill sealer sheet at the wall to joists. Why do you have that there? The batt insulation should make that connection and this is not an air barrier type of set up for that system.

2. The sill sealer below the sill plate is not standard where I have built. I would normally put that at the P.T. sill plate to concrete wall connection. Below the wall sill plate, I have been using acoustic sealant to maintain a tight air barrier.

3. I am not familiar with putting a drain pipe on the inside of the foundation walls. Is this a frost heave prevention detail?

 

image.thumb.png.2dd6961da668faf22b2035c358fa12d5.png

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If I was to review this detail as a code official, (applies prescriptively only) You didn't state which code this detail is drawn to. IRC sections quoted 

1. There is no vapor barrier shown. if the R-21 is kraft faced say so.  R702.7

2. There is no sill seal between the foundation and the treated sill plate. TABLE N1102.4.1.1 The junction of the foundation and sill plate shall be sealed

3. The stone over the footing must be 6" over the top of the footing. R405.1

4. The foundation wall needs horizontal rebar per TABLE R404.1.2(1)

 

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Thanks for that input @Bob-Roraback

Does the vapor barrier issue still apply with a conditioned crawlspace?

 

There is a thread in the Chatroom currently regarding details and who will read them. I am hopeful to see a paradigm shift that construction documents become a true instruction set for the builders. I don't want to hijack this thread but the other thread in the Chatroom will hopefully get traction to open this discussion.

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Hi Alan, For the upper exterior walls in climate zone 5 yes. I would have to look in the code if the location for this detail is in another climate zone.

The crawl space does not indicate that it is conditioned it shows that it has a vapor barrier only. Therefore, the floor insulation is required.

Also, I did not notice that the I joists are not fire protected as is required by R302.1.3

 

 

 

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7 minutes ago, Gawdzira said:

Gawdzira, 

Thanks, this is fantastic feedback!

 

> 1. the sill sealer sheet at the wall to joists. Why do you have that there? The batt insulation should make that connection and this is not an air barrier type of set up for that system.

I've never built like this but I think I saw a photo of it that way once. I presume it is to keep the untreated TJI's from contacting the concrete. If you know an alternate method to achieve that, please let me know!

 

> 2. The sill sealer below the sill plate is not standard where I have built. I would normally put that at the P.T. sill plate to concrete wall connection. Below the wall sill plate, I have been using acoustic sealant to maintain a tight air barrier.

I totally forgot the sill sealer / acoustic sealant below the sill plate! Thanks, will add!

 

> 3. I am not familiar with putting a drain pipe on the inside of the foundation walls. Is this a frost heave prevention detail?

Oops you are right, thanks! I will put some radon pipe inside the crawlspace though, but it should be just under the poly vapor barrier

 

image.thumb.png.2dd6961da668faf22b2035c358fa12d5.png

 

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20 hours ago, GeneDavis said:

Nice job.

 

For details I like solid arrowheads, and all my arrowheads are slightly smaller than my text size.  That goes for plan views and elevations, too.  

 

Examples:  All my 1/4 scale anno and dimension text is 4.5 inches tall, and all my arrows are 4.  Details at 1" scale get 1.25 inch characters and 1 inch arrows.

 

You might want the look of curved arrows instead of doing the angle break.  To curve the line, start the arrow by dragging in the direction and then hold ALT and watch what happens.  The ALT key held down enables you to curve an arrow already placed, so if I am doing curved leaders, I draw the arrows all first in the direction I want from the anno text, then go in and arrow by arrow use the ALT key and drag the arrowhead to the object or surface I want.

Nice tips and nice trick! I didn't know about ALT. Thanks!

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Thanks for all the feedback. I'll attach the updated detail.

However I realized my sill plate was exactly 8", not 7.25" as it would be if it were a 2x8. The stem wall is 8". Therefore I have a problem -- either I leave gap "A" that's unacceptable for the joist hangers, or I leave gap "B" which is a weird gap on the exterior. "A" and " are in the attached. What should I do in this situation? I assume "B".

 

(Also note Bob-Roraback I think I'm exempt from TJI underside fire membrane since I have auto sprinklers and the crawlspace has no appliances and is not intended for storage. I didn't know that though so thanks for the tip, I researched it.)

updated wall detail.png

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I would think option B is best, but you would have to be sure that the anchor bolt is in the middle third of the sill plate. R403.1.6.

Regarding the fire protection for floors, you are correct but only if you label your detail to show a plan reviewer that.

 

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3 hours ago, dnh234589 said:

However I realized my sill plate was exactly 8", not 7.25" as it would be if it were a 2x8. The stem wall is 8". Therefore I have a problem -- either I leave gap "A" that's unacceptable for the joist hangers, or I leave gap "B" which is a weird gap on the exterior. "A" and " are in the attached. What should I do in this situation? I assume "B".

 

This maybe a region specific detail ? as in many paces I've built we put a 1x2 "Pour strip" in the formwork which leaves a 3/4" x 1 1/2" rebate in the concrete and the Bottom plate is placed flush to the inside which allows the Plywood to be flush to the outer side of the FDN wall  ( and a bit of "wringle room" for out of square conditions etc), the plywood is hung down 1"-1/2", then the WRB and Siding is hung down 1" approx and 1 1/2"- 2" respectively. ( I also like a 4" tall Dripcap here to throw water off the wall , which all adds to helping seal the Air Infiltration Issue I think.)

 

* I also do it Like Gene - Solid Arrows a bit smaller than the Text size, they don't get "lost" in the rest of the hatching and Fills then.

 

M.

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In regards to your sill plate gap, both side are critical nailing locations so I would rip a 2x10 to fit.  Also, on the side where the hangers touch the P.T., I would put a strip of peel and stick Bituthane or Zip tape to isolate the metal from the P.T.. Even though you can get Zmax hangers, if you ask the engineers at Simpson (and they are being honest) they will tell you that nothing except stainless steel will survive P.T..

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I'm curious with a question to the OP. Are you a licensed architect or a 'designer' like myself?

 

The reason I ask is that I, as a designer, stay far away from details like this and have my structural engineer take care of such things. I review the details for anomalies or a misunderstanding of job site conditions but don't create the details as they tend to get in the way of actual best practice job site construction techniques. As an architect I 'might' create details of the structural engineering spec's but I have no experience as an architect so cannot speak to that issue.

 

When I was a general my brother ran our field work and he was an excellent field guy and he did not like too many details and preferred to build to code or beyond instead of trying to interpret detailed details that many times were either unbuildable or hard to interpret in the field in a way that actually made for a better constructed building. Not many of us are lucky enough to have a field supervisor that is super competent or knowledgeable and that's just one person's experience.

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2 hours ago, Gawdzira said:

In regards to your sill plate gap, both side are critical nailing locations so I would rip a 2x10 to fit.  Also, on the side where the hangers touch the P.T., I would put a strip of peel and stick Bituthane or Zip tape to isolate the metal from the P.T.. Even though you can get Zmax hangers, if you ask the engineers at Simpson (and they are being honest) they will tell you that nothing except stainless steel will survive P.T..

Treated wood is more "treated" on the outside I think? Or is it uniform all the way through? Anyway my concern would be if you rip a 2x10 and you rip off some of the more treated wood and end up with some less treated wood...


Sorry, what is PT?

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31 minutes ago, dnh234589 said:

Sorry, what is PT?

 

Pressure Treated......   and all cuts would need re-coating technically , which we all know the framer isn't likely to do as he is  "on a price", so if you were really a*** you could add a strip of 1/2 Ply instead on the inside of a 2x8 which should stop the PT Treatment eating the hangers as well. ( the new treatment is brutal even on galv'd hangers and bolts, esp. in the presence of moisture, ( look under a deck) though I think it would take decades to failure )

 

M.

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Not sure this is a good example of where a structural engineer might be helpful but a Simpson JBA hanger is intended for solid sawn lumber up against a ledger of sorts, not up against a concrete stem wall where the only attachment is on the top of the hanger. I think my engineer would suggest a ledger off the concrete wall and hang the joists from that but I don't know anything about the OP's experience or intent so very hard to say.

 

Or perhaps a Masonry hanger from Simpson? And again this is not a design I would impose upon my construction team without a S.E.'s approval and design.

 

https://www.strongtie.com/masonryhangers_masonryconnectors/category

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On 1/7/2023 at 6:19 PM, dnh234589 said:

I'm pretty new.

I created my first wall detail in Chief. It was fun! But can you tell me if I missed anything or if there is anything you would change?

 

I'm not sure if you are just new to Chief or new to the industry as well, either way Welcome. I'm suspecting that you are new to both from your post.

 

If in fact you are new to the industry there are few things to consider when you evaluate your work that you will include in your drawings. One of the biggest questions to ask yourself is how deep into pandora's box are you willing to dive? The code book in my area is in excess of 1,500 pages, how much of it do you want to include and how much of it are you willing to take responsibility for? How many times are you going to double or triple your work load because you put some little disclaimer in your general notes stating 'any deviation from the plans must be approved by the designer'? How many site managers are going to complain about your plans being too sparse / overloaded with details? As you can see from the many posts already, details, details, details .... there will be millions of details. Some details will even change as materials change - maybe you don't need wall vapour barrier if the R21 is a closed cell spray insulation?

 

I agree with HumbleChief, focus in on what you were hired to do and let other people do their jobs. Include the 'important' or 'necessary' details that need to be there but allow room for the residential family home to be flexible and change as they always do. This isn't a commercial type building and you aren't the lead engineer overriding the code book with strict tolerances. For example: your first two details R21 and 1/2" drywall. If you are going to treat this at an ultra high detail level, you would need to establish all the pro's & con's, budget impacts, better building practices, code requirements each option presents and then discuss with the owners to gain approval, as well as contact supply chains and contractor availability....just to be able to put '2lb spray foam 3-1/2" thick' with '1/2" thick moisture resistant drywall'. This is only the first two items..... of which not one person even commented on yet. You still need to go through the endless other components / systems throughout the house.

 

R21 and 1/2" drywall are perfectly fine plan details. Letting the two or three bidding builders promote their style of building with their preferred materials and price points allows you to have closure and move onto your next client. R21 is in the code book, just like anchor bolts, as well as the nailing schedule for the studs to the plates. The insulation and anchor bolts seem to always make it into the plan but very rarely does anyone even mention the spikes. What is the sense of stating 1/2"x8" anchor bolts spaced 6' apart to a pressure treated 2x6 bottom plate if you don't care about nailing the studs down??? So why is there so much discussion about one code item and not another.... it is cultural acceptance. 'Floor system as per engineered floor provider' may be all that is required, fire retardant or not, special fastener or not, maybe all the needed details are included by the supplier just like the roof trusses. Find the balance in your area and apply as necessary. The builder should know the applicable governing code book and is taking responsibility to follow it.... including the spikes and the appropriate quantity to use. Why piss him off stating that he has to use full round headed spikes if he only owns a clipped head nailer? Help the contractor make money with clear plans and he will be your referral champion. Keep the governing inspecting bodies happy and they will make your life better. Make things easier for the material estimators and they will be a referral engine for you. 

 

Research other designer's plans in your area (your local building supplier will have a good selection to look at... get to know the estimator). Do your homework as you did right here, ask everyone for feedback then adapt and change your drawings as needed for your company to become successful. Remember, most clients want you to design a wonderful house....and 1,500 pages of the code book will never fit into you plans.

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Yeah.....they went back and forth (Builder - County) 2x8 plate, cost, ¾" void, 2x10 ripped.  I just let them hash it out.  

In the end, the builder actually added a knee wall under the joists to the top of footer to ensure a solid system.  

 

All this to minimize the number of steps from garage into home.

 

 

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