# Best way to cut joists to install LVL?



## Nealtw (Jun 22, 2017)

petermole said:


> I'm preparing to take down a load bearing wall and replace it with some LVLs. I've already consulted a structural engineer and my ducks are all in a row.
> 
> 
> I'll be hiding the LVLs inside the ceiling, so I'll need to cut all the joists in the path of the LVLs. What's the best way to do this? A circular saw using some kind of fence/guide, would give me nice even cut, but of course I can't get to the end of the joist because it abuts the upstairs subfloor. A sawsall would work, but I find it hard to get a nice straight light (especially when having to reach up and cut). Is there a special tool or good method for doing this? I'll need to cut 30 2x8 joists.
> ...


 Start the cuts with the circular saw as far as you can go. 
Tack a piece of wood to the joist in line with the cut and do your best to follow that board for a reasonable cut with the sawsall .


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## Gregsoldtruck79 (Dec 21, 2017)

No special tool that I know of, and its hard work to do regardless of what tools are used. One can put a 1"x4" "guide" board vertically on the joists ( clamped or screwed ) for the circular saw floor plate to run against to get the straight vertical cut. Just set it back to allow for the saw's floor plate edge and center of the saw blade distance. 

Then, finish the top cut against the floor with a sawzall, oscillating tool wood cutting blade, or if one does not mind worn out arms...a pull saw could even be used. 

Good Luck. JMO


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## Yodaman (Mar 9, 2015)

If you have blade clearance above and below, I would use only the sawzall. Snap a chalk line across the top or bottom, then put in vertical lines on each joist using a square. Follow that line just like you would if you using a hand cross cut saw.


A typical circsaw is going to put you 1 1/2 inches away. Too far in my opinion, unless you plan on lagging a 2x board to take up the gap.


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## petermole (May 17, 2018)

Yodaman said:


> If you have blade clearance above and below, I would use only the sawzall. Snap a chalk line across the top or bottom, then put in vertical lines on each joist using a square. Follow that line just like you would if you using a hand cross cut saw.



Maybe I'm misunderstanding what you mean about "above". The 2nd floor subfloor rests on the joists I need to cut.




> A typical circsaw is going to put you 1 1/2 inches away. Too far in my opinion, unless you plan on lagging a 2x board to take up the gap.



I'm not sure what you mean by "lagging a 2x board to take up the gap".


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## Gregsoldtruck79 (Dec 21, 2017)

............................................


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## petermole (May 17, 2018)

Gregsoldtruck79 said:


> ............................................


I actually understood by your description, but hey, nice drawing! Thanks for taking the time.


It sounds like the best way is circular saw, then sawsall. I'll keep checking this thread for more replies, but I hope to start cutting by this weekend. 



Thanks for the help. :smile:


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## Yodaman (Mar 9, 2015)

petermole said:


> Maybe I'm misunderstanding what you mean about "above". The 2nd floor subfloor rests on the joists I need to cut.


 
Yea, I missed the subfloor above on the first reading. It would make the sawzall a little tough.

What is directly above?



If you have room to get the circular saw in there, then you should also be able to bring in a jig saw next. That should get you to about 1" or less from the subfloor.


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## Gregsoldtruck79 (Dec 21, 2017)

petermole said:


> I actually understood by your description, but hey, nice drawing! Thanks for taking the time.
> 
> 
> It sounds like the best way is circular saw, then sawsall. I'll keep checking this thread for more replies, but I hope to start cutting by this weekend.
> ...




..........................................."Axe" wood blade installed upside down in saw.


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## Nealtw (Jun 22, 2017)

Gregsoldtruck79 said:


> ..........................................."Axe" wood blade installed upside down in saw.


 I tack a board for the sawsall to follow too. The blade just tracks beside the board, works good when you can't things.


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## petermole (May 17, 2018)

Yodaman said:


> Yea, I missed the subfloor above on the first reading. It would make the sawzall a little tough.
> 
> What is directly above?



2nd floor covered by floating floor.




> If you have room to get the circular saw in there, then you should also be able to bring in a jig saw next. That should get you to about 1" or less from the subfloor.


I have a jig saw, and I agree it would get me closer, but I tend to get less than perpendicular cuts with it. Maye circular saw, jigsaw, then sawsall? lol.


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## petermole (May 17, 2018)

Gregsoldtruck79 said:


> ..........................................."Axe" wood blade installed upside down in saw.



NOw I feel like you're just showing off with the superfluous drawings. lol 



Axe blade, huh? Is it just a thicker blade helping with straighter cuts? I'll look for it at my local big box.


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## Nealtw (Jun 22, 2017)

petermole said:


> 2nd floor
> 
> 
> 
> ...


You sir are guilty of the dreaded over thinking a problem.:vs_laugh:
If by chance you get a really bad cut, you nail a block on the side of the joist and use a double hanger, so get at it.:biggrin2:


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## Gregsoldtruck79 (Dec 21, 2017)

And the OP has not even asked about the two temporary walls he is going to need yet .


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## Nealtw (Jun 22, 2017)

Gregsoldtruck79 said:


> And the OP has not even asked about the two temporary walls he is going to need yet .


 I think he said he had that all figured out and the cutting just made him nervous. Nobody ever thinks about just moving over a bit and doing a test cut to get a feel for what will happen.:biggrin2:


I always wished they made a blade with round nose on it for starting in plywood or sneaking up to floor like here. something like the one they make for a multi saw but just round on the end of the blade.


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## petermole (May 17, 2018)

"Nervous?" lol. I'm actually well prepared. Structural engineer has come and gone. I was just hoping for some better method or tool to make it easier. Thanks for the advice!


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## Gregsoldtruck79 (Dec 21, 2017)

The easy way, is to let someone else cut them.


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## gordon3d (Sep 20, 2021)

petermole said:


> I'm preparing to take down a load bearing wall and replace it with some LVLs. I've already consulted a structural engineer and my ducks are all in a row.
> 
> 
> I'll be hiding the LVLs inside the ceiling, so I'll need to cut all the joists in the path of the LVLs. What's the best way to do this? A circular saw using some kind of fence/guide, would give me nice even cut, but of course I can't get to the end of the joist because it abuts the upstairs subfloor. A sawsall would work, but I find it hard to get a nice straight light (especially when having to reach up and cut). Is there a special tool or good method for doing this? I'll need to cut 30 2x8 joists.
> ...


Realize this post is 3 years old but I was looking for answer to similar problem - doing structural upgrades to my deck adding a couple of 2x8s to my rim board which means cutting 2 joists at 45 degrees. I started with a 18v circular saw, then screwed in a couple of stout metal guide plates either side (see below), to guide my 18v reciprocating saw. I used a double sided metal/wood Spyder blade from Lowe’s. I finished off the last inch with a Japanese pull saw (great tool) to stop me damaging the deck boards. Process worked well with the usual hiccups as you learn from your trials and errors.


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