• Looking for a smarter way to manage your heating this winter? We’ve been testing the new Aqara Radiator Thermostat W600 to see how quiet, accurate and easy it is to use around the home. Click here read our review.

Advice on half lap joints

  • Thread starter Thread starter bsr
  • Start date Start date

bsr

Joined
5 Aug 2008
Messages
1,029
Reaction score
113
Location
Gloucestershire
Country
United Kingdom
I'm making a pair of gates and need to make 8x corner lap joints and 4x housing/cross laps in 2x4.

Here are my initial attempts at half lap joints. The smoother left one was done with a hand saw, cutting at 45 degrees from each side to avoid the cut line drifting ( I saw this on a Skill builder YouTube video). The rougher joint seems to be the favoured American way, loss of cuts with a mitre saw and then hammer. Doesn't look good to me.

Neither joint has been sanded or planed. I was thinking the left hand one would be ok if belt sanded flat but would need to make sure I didn't remove too much wood.


IMG_20250402_104739928.jpg
 
Last edited:
They are both good attempts. I gave up trying to get a perfect joint, over cut them and filled out/bonded with two part wood resin filler/glue. This was a garage door repair and was bring painted though
 
  • Thanks
Reactions: bsr
Mitre saw always going to be easiest but take time to set depth stop spot on to a fraction high (you can always shave another fraction off)
 
Neither joint has been sanded or planed. I was thinking the left hand one would be ok if belt sanded flat but would need to make sure I didn't remove too much wood.

Use a router, set to half the depth. Make the half-lap, a little way in from the end, so the router has support from both sides, then cut the surplus end off.
 
Use a router, set to half the depth. Make the half-lap, a little way in from the end, so the router has support from both sides, then cut the surplus end off.
Only have a trim router unfortunately, trying to huck out 100x100x25 would probably kill it unless I did 20 passes!
 
Only have a trim router unfortunately, trying to huck out 100x100x25 would probably kill it unless I did 20 passes!

I used a mitre saw down to 15mm and then hacked-out down to 20mm joints in C24 4x2 with a Ferrex (Aldi) palm router

Worked fine

Regards

Tet
 
  • Thanks
Reactions: bsr
when i do half lap
i trench 50/50 alternative0.5 more[deeper] than half then roughly knock the feathers off to an average 0.5 to1mm
glue and laid in position
then a baton double clamped below the join both bits and matching to the outer face off the other timber
Loosely clamp the batons top and bottom off every joint
check for square and wynd then firmly clamp till the joints are fully flush both sides

when you trench make sure you pad out from the fence to get a full width[blade centre] as a ski ramp at the edges will stop the joint closing iff too big
 
I've done 1000's over 50 years of building scenic flats. Mostly use a table saw, less tiring than a mitre saw as you are not fighting the spring all the time.
 

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Back
Top