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Old 04-17-2012, 10:58 PM   #16
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Headering off a 2x6 floor joist


I usually wait on the OP, rather than guess at spans, bearing walls, etc or answer for them........ Just showing the Code.

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Old 04-18-2012, 01:00 AM   #17
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Headering off a 2x6 floor joist


Comment from an 'average' DIY'er....

Based on my experience with my existing house and the addition I'm doing...there are good reasons they do the stuff they do....like the double joists. Yea, shortcuts might be 'ok'....but, what happens when one of your floor joists has a defect...and two people decide to take a shower at the same time?
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Old 04-18-2012, 07:45 AM   #18
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When giving advice on matters where few details are known, one should always err on the side of caution.
In my original post I didn't wade in and say 'yes, it will be fine' - I qualified it by saying that it depends on the span and how far in from the end of the beam the trimmer is.
Obviously if his 2x6s were spanning something like 13ft and the middle joist was cut out much further back I would say 'no'.

I seem to have unintentionally drawn a bit of flak on this and I'm not saying you and the others are wrong - what you are suggesting would give him a belt and braces job. What I was simply saying is that we sometimes miss more straightforward (and not, I would add, dangerous) solutions.
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Old 04-18-2012, 08:00 AM   #19
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Headering off a 2x6 floor joist


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Comment from an 'average' DIY'er....

what happens when one of your floor joists has a defect...and two people decide to take a shower at the same time?
When doing structural calculations for timber, we usually use the 'permissible stress' method. This has built-into it safety factors to allow for defects in timber such as wane and dead knots etc.

As regards overloading if 2 people take a shower at the same time; timber is well-known to be capable of taking considerably increased stress for short periods. If you and a partner had a shower for, say, 15 minutes, that wouldn't pose a problem for the joists; if you had a shower with my wife's sister, you wouldn't want to be in the shower for more than 15 seconds - even less problem for the joists.
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Old 04-18-2012, 08:32 AM   #20
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Headering off a 2x6 floor joist


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Originally Posted by tony.g View Post
In my original post I didn't wade in and say 'yes, it will be fine' - I qualified it by saying that it depends on the span and how far in from the end of the beam the trimmer is.
Obviously if his 2x6s were spanning something like 13ft and the middle joist was cut out much further back I would say 'no'.

I seem to have unintentionally drawn a bit of flak on this and I'm not saying you and the others are wrong - what you are suggesting would give him a belt and braces job. What I was simply saying is that we sometimes miss more straightforward (and not, I would add, dangerous) solutions.
Tony, this has probably gotten a bit away from us. I never said it would lead to a dangerous situation. I said it puts the adjacent joists in danger of of being overloaded, and the outcome of that could be cracked drywall joints and unwanted bounce in the floor. As GBR thankfully pointed out with a code reference, there are indeed situations where the OPs proposal would work. However, that must take into account not only the short length of the cut joist, but the long one. Both have to extend no more than 3' from a beam or load bearing wall. I simply pointed out its an unlikely scenario and that care must be taken to not misdiagnose the situation. I, in turn, got a little flak for that. So, it seems everyone is jumping on each other, and that's unfortunate. We're all just trying to help, and I apologize if my comments marginalized your input and that of others. I'm just trying to stress: better safe than sorry.

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Old 04-18-2012, 10:16 AM   #21
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Headering off a 2x6 floor joist


hi how are u.
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Old 04-18-2012, 01:26 PM   #22
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Originally Posted by cortell View Post
Tony, this has probably gotten a bit away from us. I never said it would lead to a dangerous situation. I said it puts the adjacent joists in danger of of being overloaded, and the outcome of that could be cracked drywall joints and unwanted bounce in the floor. As GBR thankfully pointed out with a code reference, there are indeed situations where the OPs proposal would work. .
Cortell; I think I understand where our difference lies - more in a moment.
I had browsed this and another US forum for some time because I am interested in domestic construction and how it differs between here and over there.
Whilst it's mainly timber frame in the US, over here it's mostly traditional masonry (brick/block; luckily we dont have seismic problems or there'd be nothing left standing!) I've learnt a lot from these forums, and although the details and terminology differ, one constant is that we all have our concerns and worries, and we all want to look after and improve our homes.
Now the crux of the problem as I understand it. I hadn't seen GBR's extract from the building Code, which is very detailed and specific. In complete contrast, British Building Regulations are written as performance specifications, and the Regs themselves are therefore very short. As long as we comply with the standards set, we can do the job more-or-less in any way we choose, so long as we can prove it complies. This is why, in the case of the OPs joists, I could not understand why so many posters criticized my approach. At least now I understand better. There are pros and cons for each system - yours probably gives more certainty and less room for dispute - ours possibly gives more flexibility.
Thanks for your posts and no hard feelings, tony.
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Old 04-18-2012, 01:58 PM   #23
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Headering off a 2x6 floor joist


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Originally Posted by tony.g View Post
Cortell; I think I understand where our difference lies - more in a moment.
I had browsed this and another US forum for some time because I am interested in domestic construction and how it differs between here and over there.
Whilst it's mainly timber frame in the US, over here it's mostly traditional masonry (brick/block; luckily we dont have seismic problems or there'd be nothing left standing!) I've learnt a lot from these forums, and although the details and terminology differ, one constant is that we all have our concerns and worries, and we all want to look after and improve our homes.
Now the crux of the problem as I understand it. I hadn't seen GBR's extract from the building Code, which is very detailed and specific. In complete contrast, British Building Regulations are written as performance specifications, and the Regs themselves are therefore very short. As long as we comply with the standards set, we can do the job more-or-less in any way we choose, so long as we can prove it complies. This is why, in the case of the OPs joists, I could not understand why so many posters criticized my approach. At least now I understand better. There are pros and cons for each system - yours probably gives more certainty and less room for dispute - ours possibly gives more flexibility.
Thanks for your posts and no hard feelings, tony.
Interesting approach. To some extent, we have a mix of both in US code books. E.g., in this particular situation, the acceptability of a solution could arguably be seen as solely needing to comply with the code-required max deflection of L/360 for floors. However, such a "dry" requirement is difficult enough for an SE to carefully calculate for a given framing solution; for a carpenter or DIYer, it's simply not practical. The problem becomes equally difficult for a compliance inspector. He has maybe five or six jobs to inspect in a day. If he has to measure the resulting deflection of this type of framing re-configuration, and similarly analyze everything else he inspects, it would take him a week to inspect a single home (or he would instead do very lax inspections). On the other hand, looking at an opening in a floor and seeing whether it meets the code requirements quoted by GBR is usually a matter of seconds.

Another example are span tables. Technically we don't need them. Most of the information in the tables could be calculated from scratch given dry requirements of E, Fb, deflection limits and many other factors. However, figuring out how deep a joist to use for a particular span would take orders of magnitude more effort than it does using a span table.

I wonder how you guys work efficiently in the absence of "user-friendly" codes, assuming I've understood you correctly.
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Old 04-18-2012, 05:03 PM   #24
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I wonder how you guys work efficiently in the absence of "user-friendly" codes, assuming I've understood you correctly.
As a matter of fact, we do have user-friendly guides to the Regulations, called 'Approved Documents'. They cover all aspects of controlled work and are just lettered alphabetically, from 'A' through to 'P'. Approved Doc. A covers structural matters, Approved Doc.B covers fire safety, Approved Doc. C covers resistance to moisture penetration etc.
They are written so that builders/architects/plan drawers can follow them easily. If we follow the guidance in these documents, it is conclusive proof to the local authority that we have complied. If we want to try something different, we can, but they are at liberty to ask for proof that we have complied. In most instances, it is just easier to follow the guidance.

Attached are some images showing a sample, from AD 'A', (structure) with diagrams showing how the standards might be met. (unfortunately they are all in SI units, which I hate, being brought up in feet and inches at school; and note the diagrams by default show masonry rather than timber structure).

Instead of using brick, it wouldn't matter if we built houses out of empty oil drums or scrap tyres as long as we are prepared to prove that they would comply!
hope U find it of interest.
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Headering off a 2x6 floor joist-scan0034.jpg   Headering off a 2x6 floor joist-scan0035.jpg   Headering off a 2x6 floor joist-scan0036.jpg  
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Old 04-18-2012, 05:18 PM   #25
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Headering off a 2x6 floor joist


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As a matter of fact, we do have user-friendly guides to the Regulations, called 'Approved Documents'.
Very interesting, indeed!
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Old 04-18-2012, 07:09 PM   #26
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Headering off a 2x6 floor joist


Here's a new question :

Would it be easier and just as acceptable to sister a 2x6 to the back side of the one that's in my way with framing nails and construction adhesive, and then notch the one that I need moved? It seems simpler as i'd only be putting in one 2x6 rather than two of them, and I don't really see why it wouldn't work if I can get it to sit on the bearing points.
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Old 04-18-2012, 07:15 PM   #27
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As you have the joists exposed to cut them anyway, just check if each header is within 3' of trimmer joist bearing, as per code:

R502.10 Framing of openings. Openings in floor framing shall be framed with a header and trimmer joists. When the header joist span does not exceed 4 feet (1219 mm), the header joist may be a single member the same size as the floor joist. Single trimmer joists may be used to carry a single header joist that is located within 3 feet (914 mm) of the trimmer joist bearing. When the header joist span exceeds 4 feet (1219 mm), the trimmer joists and the header joist shall be doubled and of sufficient cross section to support the floor joists framing into the header. Approved hangers shall be used for the header joist to trimmer joist connections when the header joist span exceeds 6 feet (1829 mm). Tail joists over 12 feet (3658 mm) long shall be supported at the header by framing anchors or on ledger strips not less than 2 inches by 2 inches (51 mm by 51 mm). From: http://publicecodes.citation.com/ico...002_par031.htm

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In response to this : 34" wide shower stall with drain centered at 17", so the joist would need to be cut at approximately 12" from the bearing point, and another cut made approximately 10 inches or so away from the first cut.

That puts both header joists within 3 feet of the trimmer joist bearing, and I only need to cut one joist so that gives my header joists a span of say 30.5" roughly as they are on 16" centers.

It sounds to me like my original plan will meet these requirements unless I am mis-interpreting something. Please advise.
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Old 04-18-2012, 07:39 PM   #28
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Headering off a 2x6 floor joist


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Originally Posted by Alan

In response to this : 34" wide shower stall with drain centered at 17", so the joist would need to be cut at approximately 12" from the bearing point, and another cut made approximately 10 inches or so away from the first cut.

That puts both header joists within 3 feet of the trimmer joist bearing, and I only need to cut one joist so that gives my header joists a span of say 30.5" roughly as they are on 16" centers.

It sounds to me like my original plan will meet these requirements unless I am mis-interpreting something. Please advise.
That's not how I interpreted it but you may very well be right. I thought each header had to be within 3' of its relative bearing point. Thus my remark regarding 7' spans. Hopefully you're right.

Last edited by cortell; 04-18-2012 at 07:55 PM.
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Old 04-18-2012, 11:44 PM   #29
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Headering off a 2x6 floor joist


Alan, if both individual headers are within 3' of same or different bearing, you will be fine, per code. "Single trimmer joists may be used to carry a single header joist that is located within 3 feet (914 mm) of the trimmer joist bearing." Bold/underline is mine.

If worried, go with your plan "B" and sister one next to the cuts. If you want/need it stronger, add plywood to the side: http://www.finehomebuilding.com/how-...-up-beams.aspx

Other choices when the floor is "bouncy" ; http://www.finehomebuilding.com/PDF/Free/021184090.pdf

You can also add 2x4 flat to the bottom of joist, but that is another discussion......

Check your span, second chart- 40# L-360; http://publicecodes.citation.com/ico...002_par011.htm

Code is minimum though there is a safety factor with the span ratings. eg.- 2x6 D.F.@ 16"o.c. w. 8' span = 89# lin.ft. or 711# dist. load Same at 9' span = 68# or 631# Same at 10' span = 56# or 568# total. From a joist/beam chart L360 w. D.f.

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Old 04-19-2012, 07:29 AM   #30
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Headering off a 2x6 floor joist


Tony and Gary, in case you're wondering...the answer is yes; I do know an ENT doctor that can remove the foot.

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