If I need to join two pieces of wood to make the overall length of a pergola longer than each individual piece of wood , would a half lap join be the correct method ?
If so how do i stop water getting in between the joints ?
In addition would coach bolts be a recommended method to ensure the horizontal pieces did not move from the vertical posts?
Thanks Andrew
This joint will not be as strong as unjoined single bit. I buy floor joists for this type of activity, most builders merchants deliver.
Rick
If you have to join two beams, try this method:-
Cut horizontally along the centre of one of the beam ends, for about a foot. Now cut down from the top of that beam at an angle of 45 degrees until you intercept your initial lengthwise cut - make sure you cut at the correct sort of 45 degrees, i.e. so you end up with an internal angle of wood. Slice the , oh stuff it, I'll try some ascii art, it never works but here goes.
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Cut one beam as shown, ( side view shown ) then the other to fit this exactly. Make the cuts at 45 degrees, the angles shown above are all I can get with ascii art. You could stick a couple of long screws through the joins, along with waterproof exterior glue to add stregth.
Andy.
Hmm, let me fix that for you (monospaced font and no tabs is the trick) ;-)
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AKA a scarf joint... another version (cuts would be smooth and not stepped in real life!) A B // //
------------------- ----------------------------- / /___ ---___ ---___ ---___ --- / /
-----------------------------/ /------------------ // // // // // // A B
Bolts right through at A and B (countersink the heads flush if you want), waterproof wood glue in the joint first.
surely it should be like this :- (if it works)
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btw as said before I would use a floor joist and not have a join
Regards Jeff
No, definitely like this:
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You did understand the bit about using a fixed-width font, didn't you?
am I seeing something different to everyone else ? it should be 2 x 45 degree cuts shouldn't it ? is this a quirk of different news readers or am I missing something ?
Regards Jeff
I'm glad you're seeing it too! Much to my amazement my original ascii art came out ok,
2 x 45 degree cuts as you say, then everyone else starts to 'correct' it with all manner of unsawable or at least impractical diagrams. I have come to the conclusion that the original sender of ascii art is unable to see it as others see it - each newsreader/mail program interprets it differently!?Andy
Yup , thats it, just had a play with OE view, text size and using the different settings you can make them all correct in turn, which means ascii art is pointless as everyone has different settings / readers
Regards Jeff
Yes, you are right. However, there _is_ a common standard for ascii art
- it must be rendered with a monospaced font (i.e. non proportional). You also need to use hard spaces to position items since tabs are not a fixed size but can be interpreted differently at whim.
Have a look at a posting on google groups:
If you use a proportional font (as OE does by default) then you have the problem that it will look wrong for anyone else not using the same font on the same platform - and in some cases you may find that getting the same representation on another platform is impossible. Whereas just about every platform has the option display a monospaced font.
If you routinely read news with a proportional font, you can switch to just about any fixed width one, and get the desired result when a diagram makes no sense. If however you read with a fixed font but need the switch to a proportional one to view a diagram, you then have the problem of which proportional font to choose since they will all make it look different!
Jeff One part may have forgotten to mention is that the joint would be on top of a post, to support the weight, I would never dream of making a joint between posts.
Andrew
In that case a short vertical lap joint with a couple of screws will suffice.
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