UGGGH A floor joist is in my way!

Jpb116 · Feb 8, 2008

I'm installing new platform tub and have discovered there is a floor joist DEAD CENTER under the tub long ways. What can be done now about the drain assembly? I can't imagine I'm the only person this has ever happened too. So, can anyone help with suggestions?

whats up · Feb 8, 2008

notch the top of the joist,then run 2+8 goeing the other direction to carry the load of the notched joist

Sponsor · 2022-01-29T12:20:58-0800

Jpb116 · Feb 8, 2008

thanks for helping ...but

not sure I understand the answer...

hj · Feb 8, 2008

drain

If it is an IPS drain fitting, then you can notch the joist at the opening and then angle the shoe to the side, After you connect the trap, then run the overflow pipe up to the opening using whatever angle fittings you need to get it positioned properly.

Frenchie · Feb 8, 2008

Plumbers!

As the friendly neighbourhood carpenter, I just want to remind you that notching is only allowed if you're close-ish to one end of the joist. No notches in the middle 3rd of the joist's span.

Also, in terms of how big your notch can be: no deeper than 1/6th the depth of the joist.

If that's not enough room for the fitting... you have two choices:

1 - redesign your layout so that the tub doesn't line up with a joist

2 do this:

EDIT: if your joists are supported, within 3' away, you can do the 1st drawing. But if their support is more than 3' away, you're stuck doing the doubled-up joists on each side, like the 2nd drawing.

GregO · Feb 9, 2008

floor joist

If there's room, I'd consider furring the wall in to allow the tub to "miss" the joist altogether. I've built (glued and screwed) additional 2x3 and 2x4 interior walls to help with this sort of scenario. I always cringe when I hear about notching or drilling joists because of the shoddy results I've witnessed all too often. Greg

Lakee911 · Feb 9, 2008

Frenchie, wouldn't you want to double up those 2x's on either side of the cut joist?

Jason

Frenchie · Feb 9, 2008

If it was a wide hole - cutting more than one joist - then yes, you'd have to sister the joists on either side, along their entire length; and also double up the headers (the 2x running at 90 degrees, that the cut joist hangs from).

For a small hole like this, only one joist cut out, singles are fine.

Statjunk · Feb 11, 2008

Ditto what Frenchie said. I'd like to add that if you have your cross members (not sure of the exact term for them) already outfitted with the hangers it makes the job a whole heck of a lot easier. Then you just pound it in run screws into the adjacent joists.

Tom

Frenchie · Feb 11, 2008

The cross members are called headers - I guess because they're positionned kinda like headers in a wall opening.

BTW, you shouldn't use screws on hangers - screws are stiffer, but more brittle - stronger in terms of pullout, but generally VERY weak in shear.

The manufacturer will specify the appropriate nail.

example:

Connector Holes and Specified Fastener Types

Simpson Strong-Tie connectors have been designed and tested for use with specific types and sizes of fasteners. Fasteners must be installed correctly to achieve published loads.

www.strongtie.com

Mikey · Feb 11, 2008

frenchie said:
BTW, you shouldn't use screws on hangers - screws are stiffer, but more brittle - stronger in terms of pullout, but generally VERY weak in shear.
http://www.strongtie.com/products/connectors/nails.asp

Well, you do learn something new every day; thanks.

Frenchie · Feb 11, 2008

Really? I'm surprised you don't know that, being in Florida, with your hurricane codes... S'why framing is always done with nails, also sheathing. Nails will pull partway out, bend... but hold. Screws'll just snap. Not only because the shank diameter's smaller, but also the hardening process (so you don't strip out the head) weakens the metal.

There's exceptions - timberlocks have a rated shear strength, as do ledgerlocks, and simpson makes some structural screws - but they're pretty specialized items, and pricey. Can be useful for situations where you need a lot of pullout resistance, though - like to attach strapping, over foam, for a rainscreen wall, in a high-wind zone; or for attaching deck ledgers.

But AFAIK, nobody in the US makes one that you can use in a hanger, or hurricane strap, or whatever.

AZ Contractor · Feb 11, 2008

frenchie said:
If it was a wide hole - cutting more than one joist - then yes, you'd have to sister the joists on either side, along their entire length; and also double up the headers (the 2x running at 90 degrees, that the cut joist hangs from).

For a small hole like this, only one joist cut out, singles are fine.

I beg to differ.

You're adding 1.5 times the load on each joist adjacent to the cut joist when you cut that 'center' joist. I'm pretty sure the floor joists are rated to carry loads up to their max and sized accordingly.

By cutting that 'center' joist you're more likely than not exceeding the max load on the adjacent joists.

I would sister another joist to them.

How much does a tub full of water weigh?

Add that to the max load on those joists and you're probably looking for trouble.

Mikey · Feb 12, 2008

frenchie said:
Really? I'm surprised you don't know that, being in Florida, with your hurricane codes...

The amount that I don't know vastly exceeds the amount that I do in all fields, and the ratio is getting worse... However, I did know that Simpson specifies specific nails for their products, just never knew why (other than for crass marketing reasons). I'm a "gotta know why" kind of guy.

Statjunk · Feb 12, 2008

The reason I said use screws is that I've had to header off joists twice in on my current project in the last year. Neither time was I able to get a hammer in there and definetly not my framing nailer. So I had to use screws. I guess I should have used deck screws. Next time.

Tom

Nate R · Feb 12, 2008

AZ Contractor said:
I beg to differ.

You're adding 1.5 times the load on each joist adjacent to the cut joist when you cut that 'center' joist. I'm pretty sure the floor joists are rated to carry loads up to their max and sized accordingly.

By cutting that 'center' joist you're more likely than not exceeding the max load on the adjacent joists.

I would sister another joist to them.

How much does a tub full of water weigh?

Add that to the max load on those joists and you're probably looking for trouble.

Maybe I'm wrong, but my line of thinking agrees w/ AZ.

Cast Iron tub is what, 300 lbs? And many tubs can hold 35 gals of water w/ no one in them, correct? 20 gals of water is about 167 lbs. Add a 200 lb person and you're looking at 667 lbs total over those 3 joists for the tub.

Also, assuming the tub is 2.5 X 5, you're looking at over 53lbs/PSF

Frenchie · Feb 12, 2008

AZ Contractor said:
I beg to differ.

You're adding 1.5 times the load on each joist adjacent to the cut joist when you cut that 'center' joist. I'm pretty sure the floor joists are rated to carry loads up to their max and sized accordingly.

By cutting that 'center' joist you're more likely than not exceeding the max load on the adjacent joists.

I would sister another joist to them.

How much does a tub full of water weigh?

Add that to the max load on those joists and you're probably looking for trouble.

Nate R said:
Maybe I'm wrong, but my line of thinking agrees w/ AZ.

Cast Iron tub is what, 300 lbs? And many tubs can hold 35 gals of water w/ no one in them, correct? 20 gals of water is about 167 lbs. Add a 200 lb person and you're looking at 667 lbs total over those 3 joists for the tub.

Also, assuming the tub is 2.5 X 5, you're looking at over 53lbs/PSF

Hmm... I'm actually reconsidering, now. When I posted, I was trying to remember @ what point you start having to double up the trimmer. My code book wasn't handy, I just recall being told not to bother, a few times in my life, framing openings for toilets and/or chimneys... but then framing's not my main thing, not by a long shot. Did a quick google, found the diagram attached below.

On the other hand, when I look in my code book - because it is handy right now - this is what I find:

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, the header joist may be a single member the same size as the floor joist.

so far so good...

Single trimmer joists may be used to carry a single header joist that is located within 3 feet of the trimmer joist bearing.

uh-oh...

So it looks like y'all are right - my earlier comments & advice are only true in very specific instances, when it's near the end of the joist span.

POST SKIMMERS, PLEASE NOTE:

THIS DRAWING IS WRONG ABOUT ALLOWING SINGLE TRIMMERS FOR HEADER SPANS UNDER 32". POSTED FOR EXPLANATORY REASONS, ONLY.

Jadnashua · Feb 12, 2008

Assuming 16"oc, the opening is less than 32"...more like 30.5" or so...sistering the outside wouldn't hurt.

Frenchie · Feb 12, 2008

jadnashua said:
Assuming 16"oc, the opening is less than 32"...more like 30.5" or so...sistering the outside wouldn't hurt.

Yeah, what I thought - but if you read my post, with the code excerpt - that illustration is wrong.

You can only use single trimmers if the opening is less than 3' away from the end of the joist span.

Lakee911 · Feb 22, 2008

It also says that end nailing is acceptable. I thought they had to have hangers, no?

In my house, built in 1923, on the end of a 13 foot span of 2x8 joists, there is a single 2x4 header supporting a single trimmer. It's within the last 24 inches or so of the bearing point. I never liked it, but it works. It looks original. Odd.

Jason

UGGGH A floor joist is in my way!

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