# double top plate and LVL



## itsnotrequired (Apr 30, 2010)

sort of hijacked another thread so i'll ask this here as a new one.

see attached photo. i am looking to 'open up' the staircase into the basement by removing the door on the right (and associated header) as well as the wall along the stairs to the left, from the stringer to the joists. replace with an LVL header and appropriate column supports in either end. already had the lumber yard size the beams and two 14"x1.75", 2.0E will do the trick, 14' long.

so my question relates to the double top plate in the area where the LVL will go. can i cut it out, such that the joists rest directly on the LVL (and providing additional studs at the ends of the LVL to reinforce the remaining double top plate)? i'd like the 3" of additional headroom if i can get it.


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## Daniel Holzman (Mar 10, 2009)

Assuming the LVL was sized to be adequate without the double top plate, you can remove the double top plate. Ask the lumber yard for the computations (if you don't already have them) so you can verify that they did not rely on the strength of the double top plate to augment their LVL selection. You probably need to submit the computations when you pull your permit anyway.


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## itsnotrequired (Apr 30, 2010)

Daniel Holzman said:


> Assuming the LVL was sized to be adequate without the double top plate, you can remove the double top plate. Ask the lumber yard for the computations (if you don't already have them) so you can verify that they did not rely on the strength of the double top plate to augment their LVL selection. You probably need to submit the computations when you pull your permit anyway.


yep, i have the calcs. they originally came back and said two 11 7/8" LVLs would do it but they were maxed out. seemed like a recipe for bouncy floors. i had them re-run the calcs with double 14" and it was much less deflection.

not sure if they ran the calcs assuming the double top plate. good catch, i'll follow up.

i asked about having to submit calcs when i pulled the permit and the inspector said no. got the permit yesterday and didn't need them. still, i wasn't going to put this thing in without having someone more qualified than me size it!


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## Daniel Holzman (Mar 10, 2009)

You should be able to easily determine if the calcs relied on the double top plate for additional strength, calcs are normally presented with assumptions written on the sheets, even if the formulas are complex and intimidating. If you cannot determine whether the top plates were includes (they most likely were not), just ask the lumber yard to verify.


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## cortell (Nov 27, 2010)

My opinion: this is a no-brainer. I would remove the double top plate without hesitation.

Here's a little test you can do:
1. Lay two thick books of similar thickness on your basement floor 14' apart.
2. Grab two 14' 2x4's and fasten them together with clamps at their ends and in the middle (or screws/nails if you don't have clamps)
3. Lay the simulated double-top plate across the books. 
4. Slightly start applying pressure with your hand near the middle of the run.
If the lumber starts bowing (which I'm sure it will), you have your answer. The double top plate's addition to the design strength of the LVL is negligible.

Excuse me while I get technical for a second. Some might object to this analysis and say: hey, what you've proved is that 2x4 lumber in that orientation has a low modulus of elasticity ("is very flexible", in layman's terms). You have not proved it has a low Fb (fiber stress in bending). In other words, if instead of books you put the plates on supports 6' off the ground, perhaps you could have a 500lb man walk across it without it snapping. Well, that's very true. I haven't proved that double top plate has a low Fb. But in this case, it's being combined with an LVL. I strongly suspect the LVL would suffer catastrophic shear failure before the double-top plates when bowed to that extreme. So, in effect, the Fb of the 2x4 in that orientation is also negligible.

All this said: I am not a mechanical or civil engineer. I just try to think like one . I'm simply telling you that in my mind, there's a near zero chance the lumber yard took into account a double top plate. If you have any doubts, though, do as Daniel said and check with them.


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## itsnotrequired (Apr 30, 2010)

Daniel Holzman said:


> You should be able to easily determine if the calcs relied on the double top plate for additional strength, calcs are normally presented with assumptions written on the sheets, even if the formulas are complex and intimidating. If you cannot determine whether the top plates were includes (they most likely were not), just ask the lumber yard to verify.


almost positive they are not included but i have asked the lumber yard to confirm. thanks for the help!

in general, it seems like the double top plate would be used with LVL during initial construction, to help keep the wall straight or to tip up walls framed on the floor. seems like once the building is finished, the top plates could be removed like i am describing without impacting the remaining wall integrity/'straightness'. is my understanding correct?


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## psilva8 (Jan 12, 2012)

Out of curiosity, what will you be using for columns and did the lumber yard detail the footings if required?


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## cortell (Nov 27, 2010)

itsnotrequired said:


> in general, it seems like the double top plate would be used with LVL during initial construction, to help keep the wall straight or to tip up walls framed on the floor. seems like once the building is finished, the top plates could be removed like i am describing without impacting the remaining wall integrity/'straightness'. is my understanding correct?


You will have to frame a temporary load bearing wall (maybe two) to remove that wall. The existing double top plates will have no role once those temporary walls are up. Unless, of course you're planning on offsetting the beam (installing it next to the existing wall)


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## itsnotrequired (Apr 30, 2010)

psilva8 said:


> Out of curiosity, what will you be using for columns and did the lumber yard detail the footings if required?


calcs indicate two 2x4 stud on each end would be acceptable but i plan on using three, just for some extra security. this is the main bearing wall which runs the axis of the house (ranch home, no second floor). the area above the bearing wall on the second floor in this area doesn't have a wall on it (just a railing, staircase opens up into the living room). underneath this wall is a 16" wide by 8" deep footing running the length of the wall with a 4" slab over the top of it. i'm thinking point loads won't be a problem at the column supports.

or maybe it is a concern?


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## itsnotrequired (Apr 30, 2010)

cortell said:


> You will have to frame a temporary load bearing wall (maybe two) to remove that wall. The existing double top plates will have no role once those temporary walls are up. Unless, of course you're planning on offsetting the beam (installing it next to the existing wall)


absolutely need a temp wall until the LVL is in, already in the plans!


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## cortell (Nov 27, 2010)

It would definitely be a concern for me. You can't assume 8" of concrete is sufficient. I would without a doubt install oversized footers for each column. 

Honestly, none of this should really be done without it being engineered. If you want to sleep well at night, spend some $ and hire an engineer. If you insist of saving that money, at least consider pouring yourself footers. I would do a 24"x24"X12", reinforced with #4 rebar 12" OC (make sure you keep the rebar 3" from the bottom of the footer)


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## itsnotrequired (Apr 30, 2010)

cortell said:


> It would definitely be a concern for me. You can't assume 8" of concrete is sufficient. I would without a doubt install oversized footers for each beam.
> 
> Honestly, none of this should really be done without it being engineered. If you want to sleep well at night, spend some $ and hire an engineer. If you insist of saving that money, at least consider pouring yourself footers. I would do a 24"x24"X12", reinforced with #4 rebar 12" OC (make sure you keep the rebar 3" from the bottom of the footer)


this seems like an awfully large footer for a column supporting floor load only in a one story home. i could see this more for a two story house with a bearing wall all the way up to the room which carries roof load, snow load, floor load, etc.


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## cortell (Nov 27, 2010)

itsnotrequired said:


> this seems like an awfully large footer for a column supporting floor load only in a one story home. i could see this more for a two story house with a bearing wall all the way up to the room which carries roof load, snow load, floor load, etc.


I absolutely agree with you. And if a licensed engineer said that, I'd say to him "let's go with whatever you suggest." However, if I'm bypassing an engineer, I'm going to over-engineer it so I can sleep well at night.


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## itsnotrequired (Apr 30, 2010)

cortell said:


> I absolutely agree with you. And if a licensed engineer said that, I'd say to him "let's go with whatever you suggest." However, if I'm bypassing an engineer, I'm going to over-engineer it so I can sleep well at night.


i appreciate the concern. i thought about the column point load and the footing seems large enough but i'm going to bounce it off a couple engineer friends i have, just to get their opinion.


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## cortell (Nov 27, 2010)

itsnotrequired said:


> i appreciate the concern. i thought about the column point load and the footing seems large enough but i'm going to bounce it off a couple engineer friends i have, just to get their opinion.


Believe me, if I had auto mechanic friends, I wouldn't bring my car to a shop either. 

It sounds to me like you're thinking this through fairly well and not winging it. I predict you'll be quite successful with this project.


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## itsnotrequired (Apr 30, 2010)

cortell said:


> Believe me, if I had auto mechanic friends, I wouldn't bring my car to a shop either.
> 
> It sounds to me like you're thinking this through fairly well and not winging it. I predict you'll be quite successful with this project.


thanks for the encouragement. yes, lots of late nights researching, planning, etc!

beam sizing was a little funky as well (but no problem for the sizing software). hard to tell from the photos but the joists above the doorway are continuous spans (16" OC), joists further to the left are simple spans (16" OC) and the joists on the far left are also simple spans but 12" OC. certainly not the type of arrangement that is outlined in a basic load table.:laughing:


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## cortell (Nov 27, 2010)

itsnotrequired said:


> beam sizing was a little funky as well (but no problem for the sizing software). hard to tell from the photos but the joists above the doorway are continuous spans (16" OC), joists further to the left are simple spans (16" OC) and the joists on the far left are also simple spans but 12" OC. certainly not the type of arrangement that is outlined in a basic load table.:laughing:


No kidding. In a situation like that I would assume a consistent layout, and use the weakest of the configurations. I.e., I would ignore the 12" OC joists and assume they're all 16". If for some crazy reason there are 2x8 joists in part of the floor but 2x10s elsewhere, I'd assume they're all 2x8. I rather simplify and over-engineer in some places than sweat out the variations.


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## itsnotrequired (Apr 30, 2010)

cortell said:


> No kidding. In a situation like that I would assume a consistent layout, and use the weakest of the configurations. I.e., I would ignore the 12" OC joists and assume they're all 16". If for some crazy reason there are 2x8 joists in part of the floor but 2x10s elsewhere, I'd assume they're all 2x8. I rather simplify and over-engineer in some places than sweat out the variations.


all joists are 12" deep wooden i-joists. the 12" OC joists are due to the span length. there is a bumpout on the opposite wall (the one behind me in the photo) which takes the span from 16' to 20'. looks like the builder was able to get by with 16" OC on the 16' spans but needed 12" OC on the 20' spans to maintain the same elevation on the bottom of the joists. much better than going to deeper joists and breaking the ceiling line.


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## cortell (Nov 27, 2010)

itsnotrequired said:


> all joists are 12" deep wooden i-joists. the 12" OC joists are due to the span length. there is a bumpout on the opposite wall (the one behind me in the photo) which takes the span from 16' to 20'. looks like the builder was able to get by with 16" OC on the 16' spans but needed 12" OC on the 20' spans to maintain the same elevation on the bottom of the joists. much better than going to deeper joists and breaking the ceiling line.


Absolutely. That's what's nice about designing a floor for 16"OC joists. You can bump it up to 12" (or "to 11", as Nigel Tufnel would say) as needed--a span that is an even multiple of the all-so-important 48" and which is also, thankfully, covered by the span tables.


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## itsnotrequired (Apr 30, 2010)

cortell said:


> Absolutely. That's what's nice about designing a floor for 16"OC joists. You can bump it up to 12" (or "to 11", as Nigel Tufnel would say) as needed--a span that is an even multiple of the all-so-important 48" and which is also, thankfully, covered by the span tables.


builder laid out the basement with the idea that someone may want to finish it one day. there is not a single pipe, duct, cable run, framing member, support post/beam, etc. below the joists or on the walls on the side i am looking to finish (where i took the photo). other side of the wall is a utility room which has everything. very nice.

in our old house, joists were 19.2" OC. finally figured out what those goofy diamonds were on the tape measure that didn't seem to line up with anything.:laughing:


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## woodworkbykirk (Sep 25, 2011)

from what i can see from that photo the rough opening for the door is already framed wrong.. there is a double top plate.. then a filler peice of 2x under teh top plate which is in turn on top of the lvl then yet again a doubled lintil 

the lvl should be directly under the double top plate first off to elminate as much chance of shrinking and crush under the load of the above floor system and any bearing walls on top of that

if you take out the double top plate though its still going to be extremely strong.. 2x material on its flat isnt as resistant to being crushed like it is on end or to a engineered beam


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## itsnotrequired (Apr 30, 2010)

woodworkbykirk said:


> from what i can see from that photo the rough opening for the door is already framed wrong.. there is a double top plate.. then a filler peice of 2x under teh top plate which is in turn on top of the lvl then yet again a doubled lintil
> 
> the lvl should be directly under the double top plate first off to elminate as much chance of shrinking and crush under the load of the above floor system and any bearing walls on top of that
> 
> if you take out the double top plate though its still going to be extremely strong.. 2x material on its flat isnt as resistant to being crushed like it is on end or to a engineered beam


the photo is the existing installation and what it looked like when i moved in. the door header is standard 2x10 lumber. it would get yanked out as part of the lvl beam install. beam will be 14' long and replace the existing door header and most of the staircase wall.


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