Fitting skirting and architrave

[Deleted member 174758]

On a piece with a single scribed end it's normal to cut a bit (30 to 40mm) over length, make the bevel cut, scribe the end, adjust the scribe, then make the mitre cut at the other end. Trying to do a scribe at both ends is very difficult, hence the reason you should always plan your work to avoid double scribes if at all possible (but there us a technique to deal with this)

BTW too much foam, and/or wrong type of foam

plasterers don’t make the plaster down near the floor terribly flat….it tends to belly out a bit. So skirting never sit nice and plumb.

I know they don't. It's the start of their "stroke" so they often don"t get the pressure right. Some plasterers are than others, though, whilst for the worst ones there"s always a hammer and an electrician's bolster (yes, really!) - I just make sure that any butchery is below the line of the skirting top

 

[Keitai]

On a piece with a single scribed end it's normal to cut a bit (30 to 40mm) over length, make the bevel cut, scribe the end, adjust the scribe, then make the mitre cut at the other end. Trying to do a scribe at both ends is very difficult, hence the reason you should always plan your work to avoid double scribes if at all possible (but there us a technique to deal with this)

BTW too much foam, and/or wrong type of foam


I know they don't. It's the start of their "stroke" so they often don"t get the pressure right. Some plasterers are than others, though, whilst for the worst ones there"s always a hammer and an electrician's bolster (yes, really!) - I just make sure that any butchery is below the line of the skirting top

When cutting out the scribe at the top of a bull nose or whatever I seem to chip the thin top corner off. Shall I cut outwards or start from the top or just be more careful?

 

[foxhole]

If you use too much foam you leave it to cure then it’s easily trimmed with a knife.

 

[Deleted member 174758]

Set your coping saw blade so that the teeth point towards the handle - this makes the saw cut on the pull stroke. (I am now going to be told by loads of people that I am wrong - those people have obviously never used a fret saw or a Japanese saw, that's for sure) Doing this means that the blade is in tension when cutting (i.e it is stiffer) and will therefore run straighter/cut truer on a pull stroke. If you learn to use it like a fretsaw, with the finished surface uppermost and clamped to something sturdy, and with the handle below the material, making a downward cut, you won't get as many blow outs - and if you do get a few they will be on the underside (i.e at the back of the material) where they can't be seen. Only downside is that it takes a bit of practice to master this technique. I also use a similar technique with a jigsaw and a Collins coping foot

Start your vutd at the top snd limit your cutscto just past the start of.the straight bit. Remember to put a small bit of undercut on it. A rat tail rasp csn be useful.if doing largd numbers to clean up cuts that are slightly out

Cut the straight bit with a fine handsaw, again with a few degrees of undercut (or if really proficient a portable curcular saw, mitre saw or jigsaw can be used). This is the section you may need to recut to handle out of plumb skirtings

 

[Deleted member 174758]

If you use too much foam you leave it to cure then it’s easily trimmed with a knife.

Yes, but the decos go nuts with you if you do that because their paint doesn't stick or something

 

[Notch7]

I know they don't. It's the start of their "stroke" so they often don"t get the pressure right. Some plasterers are than others, though, whilst for the worst ones there"s always a hammer and an electrician's bolster (yes, really!) - I just make sure that any butchery is below the line of the skirting top

when I was building orangeries, I used to get the plasterers to fit a stop bead about 50mm up from FFL. It works a treat for getting a flat wall at skirting level.

 

[Keitai]

I'll practice that.

With the architrave do you just cut the two side pieces to the right length? I noticed they're almost the right length already. Then pin then cut top bit too long then cut and cut until it fits?

 

[Deleted member 174758]

Mark out the set back on the jambs and head of the casing/lining using a combi square (normally 10mm ser back in traditional work, 5mm in modern work). Measure the length of the head where the set back lines cross in the top corners. Cut a piece of architrave forvthe head with two, opposite mitres, one at each end. The inside mitre length will be the length you have just measured. Allow extra for the mitres, 1-1/2 times the width of the architrave onto each end.

So assuming door t opening of 768mm, the vertical "ticks" on trad work.would be at 788mm apart (10mm set back each side). If your architrave is 70mm wide, you'll therefore need to add 2 x (70 × 1.5)mm to the measured length between the ticks to get the slightly over length piece of archi yoneed f to start with:

788mm + (2 x (70 x1.5)) = 788 + 210 = 998mm

Cut the left hand mitre. Measure out to the corner point (788mm in this example) then cut the second mitre. Pin the head in place aligning with your tick marks

Measure from the top of the architrave head to the floor on both sides. Cut a pair of archi legs (a matching pair) with a square bottom and a mitred top to the longer of those two lengths plus 5 mm. So if the heights from the top of the architrave head to the floor were 2077 and 2086mm respectively you'd cut a pair of legs, one right, one left hand 2091mm long to the long points (2086 + 5mm). Pop the archis on the correct sides of the door openingStarting g with the left one invert the archi leg so the point is on the floor and the flat bottom is resting against the left corner point of the archi head. Transfer the position of the top of the header onto the bottom of the leg. Crosscut the leg to length (thisvis a square cut). Invert the leg againtoso.it is now the right way up), add Mitra Mate to the mitre faces (glue to one mitre face, spray hardener to the other), quickly position the archi leg and hold in the correct place for 15 seconds whilst the glue sets. Pull the leg gently to align to the tick marks on the jamb, as required then pin or nail in place. Repeat for the other leg. Sand off the mitre joints (or at leastbthe flat parts) with a sanding board (piece of 18mm MDF, maybe 200mm long x 100mm wide with a piece of sandlng paper attached (spray adhesive)

It's not that difficult. I've done thousands of them

 

[Keitai]

Mark out the set back on the jambs and head of the casing/lining using a combi square (normally 10mm ser back in traditional work, 5mm in modern work). Measure the length of the head where the set back lines cross in the top corners. Cut a piece of architrave forvthe head with two, opposite mitres, one at each end. The inside mitre length will be the length you have just measured. Allow extra for the mitres, 1-1/2 times the width of the architrave onto each end.

So assuming door t opening of 768mm, the vertical "ticks" on trad work.would be at 788mm apart (10mm set back each side). If your architrave is 70mm wide, you'll therefore need to add 2 x (70 × 1.5)mm to the measured length between the ticks to get the slightly over length piece of archi yoneed f to start with:

788mm + (2 x (70 x1.5)) = 788 + 210 = 998mm

Cut the left hand mitre. Measure out to the corner point (788mm in this example) then cut the second mitre. Pin the head in place aligning with your tick marks

Measure from the top of the architrave head to the floor on both sides. Cut a pair of archi legs (a matching pair) with a square bottom and a mitred top to the longer of those two lengths plus 5 mm. So if the heights from the top of the architrave head to the floor were 2077 and 2086mm respectively you'd cut a pair of legs, one right, one left hand 2091mm long to the long points (2086 + 5mm). Pop the archis on the correct sides of the door openingStarting g with the left one invert the archi leg so the point is on the floor and the flat bottom is resting against the left corner point of the archi head. Transfer the position of the top of the header onto the bottom of the leg. Crosscut the leg to length (thisvis a square cut). Invert the leg againtoso.it is now the right way up), add Mitra Mate to the mitre faces (glue to one mitre face, spray hardener to the other), quickly position the archi leg and hold in the correct place for 15 seconds whilst the glue sets. Pull the leg gently to align to the tick marks on the jamb, as required then pin or nail in place. Repeat for the other leg. Sand off the mitre joints (or at leastbthe flat parts) with a sanding board (piece of 18mm MDF, maybe 200mm long x 100mm wide with a piece of sandlng paper attached (spray adhesive)

It's not that difficult. I've done thousands of them

I didn't think it would be so complicated.

Basically 5mm all round from edge and you recommend glueing the joins as well as pinning the lot. I'll use wood glue or pink stuff to glue joins and I'll pin the rest. I'll read it all again tomorrow to try and understand it

I had a go at cutting on pull in photo.

 

[Deleted member 174758]

That is not complicated - putting a cut roof on a listed building, now that can be complicated. At the end of the day (and with the exception of the use of Mitre Mate) it is how carpenters have done the job for generations. Or in other words there really is some skill involved in my chosen trade

You don't use any glue whatsoever on the architraves other than Mitre Mate on the faces of the mitres. Do not use pink foam on the mitres because it will open up the mitres - they are supposed to be tight. You can't fill gaps in mitres - that will always show and looks really amateurish. Do not use PVA - it does not set fast enough, nor hold well enough. Do not put them together dry - the joint will potentially open up over time. We use Mitre Mate (or Mitre Bond, or any of the other 2-part mitre adhesives) specifically because it ensures that the mitres don't open up over time. At one time we needed to "pin the ears" of the mitres which always risked splitting them and was never a 100% solution. The modern way is far, far superior

The method described also allows you to set up a mitre saw in a fixed location and tackle an entire (small) house without the need to move the saw, so you can "bulk cut" the legs and trim the legs to length when you install them. Cuts to length require only a try/combi square and a hand saw. Doing this for a living you need to do 2 to 3 architrave sets (i.e both sides of a doorway) an hour to earn the money, so it should be a quick process

BTW don't just arbitrarily choose a 5mm set back. On a new build the architect often specifies the set back. On an existing build you need to use your combi square to transfer the set back from an existing doorway (note that you do not measure the set back with a tape - the combi square acts as gauge). I was taught that you only measure where absolutely necessary - a gauge or a rod is a far more accurate and consistent way to deal with transferring multiple repeated measurements (and this requires 3 to 4 "tick marks" up each jamb plus three along the top, so repeat markings to set out)

How did you find the down cut approach? Slightly more awkward to do, but more controllable cut and less breakouts?

On the issue if coping saws and blades, cheap Chinese coping saw frames are carp. A good frame costs relatively little. Yours looks like an Eclipse (Spear and Jackson) but other good makes include Bahco, Ohlsen (American), Stanley and Irwin. All these manufacturers make decent quality blades - avoid cheap Chinese ones because many just don't work well. Best blades I've ever found are Pegas

 

[Keitai]

That is not complicated - putting a cut roof on a listed building, now that can be complicated. At the end of the day (and with the exception of the use of Mitre Mate) it is how carpenters have done the job for generations. Or in other words there really is some skill involved in my chosen trade

You don't use any glue whatsoever on the architraves other than Mitre Mate on the faces of the mitres. Do not use pink foam on the mitres because it will open up the mitres - they are supposed to be tight. You can't fill gaps in mitres - that will always show and looks really amateurish. Do not use PVA - it does not set fast enough, nor hold well enough. Do not put them together dry - the joint will potentially open up over time. We use Mitre Mate (or Mitre Bond, or any of the other 2-part mitre adhesives) specifically because it ensures that the mitres don't open up over time. At one time we needed to "pin the ears" of the mitres which always risked splitting them and was never a 100% solution. The modern way is far, far superior

The method described also allows you to set up a mitre saw in a fixed location and tackle an entire (small) house without the need to move the saw, so you can "bulk cut" the legs and trim the legs to length when you install them. Cuts to length require only a try/combi square and a hand saw. Doing this for a living you need to do 2 to 3 architrave sets (i.e both sides of a doorway) an hour to earn the money, so it should be a quick process

BTW don't just arbitrarily choose a 5mm set back. On a new build the architect often specifies the set back. On an existing build you need to use your combi square to transfer the set back from an existing doorway (note that you do not measure the set back with a tape - the combi square acts as gauge). I was taught that you only measure where absolutely necessary - a gauge or a rod is a far more accurate and consistent way to deal with transferring multiple repeated measurements (and this requires 3 to 4 "tick marks" up each jamb plus three along the top, so repeat markings to set out)

How did you find the down cut approach? Slightly more awkward to do, but more controllable cut and less breakouts?

On the issue if coping saws and blades, cheap Chinese coping saw frames are carp. A good frame costs relatively little. Yours looks like an Eclipse (Spear and Jackson) but other good makes include Bahco, Ohlsen (American), Stanley and Irwin. All these manufacturers make decent quality blades - avoid cheap Chinese ones because many just don't work well. Best blades I've ever found are Pegas

Ok I'll glue the mitre joints on architraves. Wood glue ok? And must I use mitre mate on skirting mitres too?

 

[Notch7]

We use Mitre Mate (or Mitre Bond, or any of the other 2-part mitre adhesives) specifically because it ensures that the mitres don't open up over time

I hadn’t realised pro chippies used mitre mate for door archs these days.

Although TBH, no glue will keep a mitre closed against timber shrinkage - because timber will shrink most on its width, that means mitres end up opening up.
Having said that, I guess superglue will hold the mitre strongly in place against door liner movement.

My background is more manufacture than site work - I’ve been doing some sitework recently and I do struggle with it…..I seem to spend all day going back to the van for stuff.

 

[Keitai]

The architrave on the right isn't on a flat surface. Should I chip it back level? Cand butt it up to hinge? On left I guess need to cut it thinner to fit

 

[Deleted member 174758]

Ok I'll glue the mitre joints on architraves. Wood glue ok? And must I use mitre mate on skirting mitres too?

Use mitre glue for the architrave mitres. I also use it for mitres on skirtings (outside corners only, obviously). If you are skirting around a column, for example (not common in domestic properties, quite common in commercial spaces), it can be very handy to make up your skirting as two L-shaped legs first then join them together around the column (note that in high traffic environments it is normal to cross pin outside corners)

 

[Deleted member 174758]

I hadn’t realised pro chippies used mitre mate for door archs these days.

Yes, quite a lot of guys do use mitre adhesives these days, especially with MDF and the ropey softwood we see so much of. With either of those you will find that trying to pin through the mitre ("pinning the ears") will result in splitting more often than not unless care is taken to pilot the nails (and lets face it who the blazes would bother to do that)

Hardwoods are sometimes joined with Hoffman dovetail joints, a mechanical fastening, or glued biscuits, or even the old fashioned pilot drill and crossed hidden pins.

Non of these techniques completely stop mitres opening, but if the wood is finished (painted, lacquered, etc) shortly afterwards it will not often occur as the timber is sealed

My background is more manufacture than site work - I’ve been doing some sitework recently and I do struggle with it…..I seem to spend all day going back to the van for stuff.

Organisation is key. That and being able to make do without all the bells and whistles (or in other words be able to say "b@ll#x" when you've left your jigsaw in the workshop, but still produce an acceptable scribe using a bread knife and a cheese grater)