Cutting notches

On 03/09/2013 15:13, snipped-for-privacy@gglz.com wrote: .

2.18m
I could notch a bit less ... say 25mm.
Most Pergola plans only use 3x2 cross timbers.... went up to 4x2 (equiv) to avoid sag. There is no load on these ... all they support is themselves.
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My old copy of Part A (when it still had span tables), sets the limit to 2.02m for a 400mm joist spacing. That's for a building floor of course. So your 2.18m span doesn't sound out of order.
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On Tue, 3 Sep 2013 07:13:37 -0700 (PDT), snipped-for-privacy@gglz.com wrote:

Which is why I'd take 15 mm from each. It would also mean that the smaller timber wouldn't need any additional fixing to stop it sliding sideways along the top of the larger. Niether bit would be able to move relative to the other.
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On 03/09/2013 12:02, snipped-for-privacy@gglz.com wrote:

But a half lap, once glued, isn't a notch.
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Dave - The Medway Handyman www.medwayhandyman.co.uk

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On 03/09/2013 22:51, The Medway Handyman wrote:

Wood glues provide considerable shear strength, but not much tensile strength. In your half-lap, the "filled" notch on the compression side gives you back just about all of the strength. But the notch on the tension side depends on the tensile strength of the glue. So (assuming it is a "floor" with the loads downwards) you want the notches in the top face of the "more important" timber.
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wrote:

Exactly so. But best avoided altogether if possible as the components will need to be oversized.
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On 06/09/2013 07:28, harryagain wrote:

Dagenham.
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On Mon, 2 Sep 2013 06:16:44 +0100, harryagain wrote:

Only because any monkey can wield a hammer but it takes time and a bit of skill to cut, accurate, tight fitting notches. I'd be inclined to notch both bits of timber half the required depth than notch just one the full depth though.
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On 02/09/2013 06:16, harryagain wrote:

This is not for house construction, and it is decorative so having any steel ties is not an option.
Your points on construction are correct.
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On 01/09/2013 23:08, Rick Hughes wrote:

Dado blades aren't allowed in the UK because of Effin Softy.

I do this all the time, notching newel posts for decking.
Circular saw set to the depth you want. Use a rafter square, home made jig or one of these;
(Amazon.com product link shortened)78107141&sr=8-11&keywords=kreg
to ensure a square cut. Cut each side accurately, then make a series of free hand cuts a few mm apart (working right to left, so the base of the saw is supported).
Knock out the waste & trim with a sharp chisel.
Fast & accurate.
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On 02/09/2013 08:43, The Medway Handyman wrote:

+1 but Harry may have a point
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On 02/09/2013 09:48, stuart noble wrote:

You need to consider how the thing is loaded and what you are nothing. If you notch the top of a joist, and then fill it with a tight fitting cross member, you will not lose much strength.
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You're kidding, right? A google search yields dozens of UK sources.
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Today is Setting Orange, the 26th day of Bureaucracy in the YOLD 3179
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On 02/09/2013 10:11, Huge wrote:

I did a lot of searching on w/end on this .... Dado blades are not something that can be attached to your average DIY saw table ... as arbor length is not long enough. Several DIY tables specifically state that a you must NOT fit a Dado blade.
They are available for Commercial (Wadkin etc.) table saws, but elfen safely does come into this .... in a Commercial use, there is a required maximum duration for blade to come to a stop after stop is pressed, and fitting a Dado blade will normally cause saw to exceed this.
The way around is that they then have to fit a DC brake to ensure it stops within required time.
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On Monday, 2 September 2013 11:37:45 UTC+1, Rick Hughes wrote:

Lots of older (large/pro) tale saws needed DC brakes fitting to them to meet regs, even without a dado set. Inverters can do all that now.
AIUI since the HSE banned the use of dadoes, they did it by specifying the max length of arbor on new table saws on sale - not by banning the sale of dadoes.
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On 02/09/2013 12:08, snipped-for-privacy@gglz.com wrote:

Did they actually ban dado sets though? or just specify a maximum stop time?

Does not seem to be a problem on my 1948 Unisaw ;-)
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On 02/09/2013 13:28, John Rumm wrote:

Did admit to being tempted with the large number of Wadkin saws on ebay ... incl the tilting table versions
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On Monday, 2 September 2013 13:51:00 UTC+1, Rick Hughes wrote:

I bought an old 3 phase Startrite bandsaw and fitted an inverter to run it off single phase. When I have a suitable location there'll be a Wadkin or similar mahoosive old-british table saw too.
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Both.
Industrial woodworking machines have a maximum time for the blade to come to rest, and this applied retrospectively, hence many machines with DC braking retrofitted.
I think dadoes were also banned in industry (i.e. you had to discontinue using them), *and* a maximum length of arbor specified for all new machines sold.
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On 02/09/2013 17:02, snipped-for-privacy@gglz.com wrote:

Yup I was aware of the time limitation, and also the short arbour problem. Just not sure if there was actually an industrial ban on dadoes as such. They don't strike me as particularly dangerous (compared to wobble blades say).
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