Masons Mitre joint excess

[Mountain mj]

I am going to order a new worktop but I'm unsure how much excess is required to do a masons mitre joint.
I'm getting the worktop cut to size but I dont think they'll supply it with the masons mitre joint already cut. So I need to get the joiner to do that bit for me on site.

My current worktop is 2680mm end to end of the mason mitre joint and 2645mm end to the start of the masons mitre (see picture). The worktop I've been quoted for is 2780mm which means the joiner will only have 10mm to play with. Is this enough? What would you recommend as an excess?

Thanks

 

[Deleted member 174758]

If a joiner is installing it why do you need it cutting to size? Laminated worktops mostly seem to come in 3m and 4m lengths, ex-factory, and I'd expect to cut them to length and do the cut-outs when I install them. If your corner is even slightly out of square (and most buildings seem to be a bit out - the older they are, the worse they are) then your joiner will need a bit of extra leeway in the joint in any case - and personally I always like to cut the joint then trim to final length just in case the corner isn't square and I need to adjust the cut, or the laminate chips out (it happens occasionally). If you insist on a piece being delivered dead to length (or with a 10mm margin) then you are painting the joiner into a corner and giving him absolutely no leeway to deal with problems. As a joiner, I for one wouldn't be happy about you doing that to me. So, what has your joiner said about this and why do you need the factory to do the cutting? (and if they are doing the cut-outs, maybe they should be responsible for the installation as well)

 

[Mountain mj]

Thanks JobAndKnock. The worktop i'm planning on buying comes in any size you want, not the standard 3/4m lengths. I provided the pictures with the measurements and they came back with a quote with the extra 10mm. I havent got a joiner yet hence why I am asking. I thought 10mm was not enough which is why I was asking how much is enough. Presumably just take it up to 3m from what you said? I'm not insisting on anything - that's why I am asking before buying.

 

[Deleted member 174758]

In that case I'd maybe allow about 100mm over length on both joints to give your man enough leeway on the joints. My current Trend kitchen worktop joint jig allows for inset depths of 3, 5, 10, 24 and 35mm (older jigs tend to be just 35 or 24mm) - the inset depth depends on the edge profile of the worktop, so generally the 24mm or 35mm I'd use for a post-formed top with a large edge radius whilst 3 and 5mm are for nearly square edges with a slight radius (e.g solid wood tops and some solid laminate tops), and the 10mm is somewhere in between.

Forgive my caution, but I have in the past been presented by kitchen manufacturers with worktops which were pre-routed dead to size with the cut-outs and joints "ready to install" only to discover that the units weren't quite in the same positions that the drawing said they would be and that the corners of some of the kitchens weren't quite square. Real life isn't quite as perfect as the guys in workshop sometimes think it is, I'm afraid. Even a couple of degrees off square in a corner makes quite a difference to the length of the male piece in particular (angle adjustment is always made on the male piece as it is far easier to do this). 100mm also covers you against damage in transit - another thing which happens from time to time

 

[Mountain mj]

Thanks for the informative answer. I am aware that my measuring is only a guide and until the worktop is going down those measurements are only good as a rough guide. If I had gone ahead and bought exact measured worktops it wouldve been 100% my fault when they inevitably dont fit.

Thanks again

 

[TimboTwo]

2780 - 2680 = 100mm.
Personally I wouldn't be keen on the sink that tight on the corner, very weak point for handling the worktop.

 

[Mountain mj]

2780 - 2680 = 100mm.
Personally I wouldn't be keen on the sink that tight on the corner, very weak point for handling the worktop.

Yes I realised after that it's 100mm. The sink is already there. Those measurements are from what is the currently so it should be fine