creating recess in timber joists

[gwilo-1]

Hi i am trying to fInd the most suited tool for recessing into floor joists

I install prefacbricated stepless showerbases. With some larger sizes, the thickness of these bases are thicker,which requires joists to be recessessed so showerbase is at level entry with subfloor.

What is the most effective way to recess the joists at exactly the same depth which can be up to 10mm max.?

I have tried using my circular saw wigh a rip guide but always end up using chisel and hammer as my saw wont always fit between the spaces of joists.

I was thinking somethIng lIke a biscuit cutter or router but am not familiar with their limitations so cant afford to pocket out money just for the sake of trying. And a planer can only do certain depths and a lot of playing around.

can anyone help?

[artme]

Don't quite understand wht you mean by recesses and where they are.

Woul a router do the job?

[Handyjack]

Would one of these help?
http://justtools.com.au/multi-purpose-sander-a-cutter
You might use it in combination with another tool such as a circular saw to start and finish cuts.
Cheaper versions are available as are cordless. Festool is releasing theirs next year.

[ian]

Biscuit jointer to make a series of cuts across the joist to the required depth.
Space the cuts just greater (2-3mm) than your chisel is wide, then use a hammer and chisel to knock out the "blocks"

Did something very similar to take 3/4" off the wall studs 16 years ago to install a bath

[Skew ChiDAMN!!]

A router and jig might be what you're looking for.

The jig is more or less just a cradle that drops down over each joist to control depth of cut.

It's a method I've used for what I think may be similar jobs... although I too revert to hammer & chisel when up against floor plates, etc. (Why do people always insist on putting showers against walls? :innocent:)

[Chris Parks]

Work out the height you need to drop it to and using a router and jig put trenches across the top of the joist and hand chisel between the trenches. It should go pretty quickly I would have thought. A multi tool would work but I reckon the router and chisel would be quicker.

[rwbuild]

Ian nailed it in one! the only thing I do different is use it like a circular saw, push in then slide in the correct direction relative to rotation, do from both sides of joist, saw cut each end or sharp chisel, job done.

I also use the biscuit joiner to make rebates in the edges of boards to join them, also grooving bottom of doors for sliders, or anything that requires a grove or rebate.

Multitude of uses

The other alternative is a dedicated small circ saw with a timber fence permanently mounted to the sole plate and slotted for adjustment and held in place by 2 wing nuts

[gwilo-1]

Thankyou to everyone for your input. I think i might try the biscuit joiner. I generally do renovation work so deal with a lot of hardwood. Is it as effective on hardwood?

[Bob38S]

Should be OK,

but, personally, I would go the router jig, particularly as it appears you need this to be done more than once.

Easy to set up

Length or depth adjustable

Quick to use

Consistent smooth depth

Just my thoughts.

[ian]

Thankyou to everyone for your input. I think i might try the biscuit joiner. I generally do renovation work so deal with a lot of hardwood. Is it as effective on hardwood?a biscuit jointer is basically a 4" dia saw, with a built in depth of cut gauge. Set the saw extension to 10mm say, and then plunge the blade across the joist to cut a series of slots which will then make chiselling out much easier

[rwbuild]

a biscuit jointer is basically a 4" dia saw, with a built in depth of cut gauge. Set the saw extension to 10mm say, and then plunge the blade across the joist to cut a series of slots which will then make chiselling out much easier

No need for a series of slots, plunge then slide like a circular saw SLOWLY not too fast

I suspect you are talking predominately first floor wet areas with either pine or I joists (Hyspan) and if they are I joists you have VOIDED ALL WARRANTIES and leave yourself wide open to legal action if anything goes wrong

LVL,s are ok as is solid pine joists.

Do yourself a big favor, get the builder to check with their structural engineer because if the joists are only just meeting the design criteria, anything which is deducted could affect its design strength and the builder will pass the buck to you

[ian]

No need for a series of slots, plunge then slide like a circular saw SLOWLY not too fast

I suspect you are talking predominately first floor wet areas with either pine or I joists (Hyspan) and if they are I joists you have VOIDED ALL WARRANTIES and leave yourself wide open to legal action if anything goes wrong

LVL,s are ok as is solid pine joists.

Do yourself a big favor, get the builder to check with their structural engineer because if the joists are only just meeting the design criteria, anything which is deducted could affect its design strength and the builder will pass the buck to youGood point Ray

but I gather these showers are retrofits

If the joists are I beams -- the best advice might be don't touch

[rwbuild]

In some circumstances, it could be ok ie depth of joist relational to span between supports but I agree, if in doubt, DON'T until checking with a structural engineer

Some will say 10mm ain't much but when the joist is already at its design limit, :no::no::no:

[ian]

Some will say 10mm ain't much but when the joist is already at its design limit, :no::no::no:If I'm reading the Hyspan I-beam drawings correctly, 10mm can be over 1/2 the flange thickness
definitely not a good idea :no: