Skotia & Architraves

Attached the skotia's today for the most of the morning, after learning how to do it last week on Wednesday.

Was quite a easy process, but you really had to concentrate when cutting the skotia that you had made the correct measurements firstly, but also that the right angle for the join is made.  The edge that is exposed to the open should be sanded back so that it isn't too sharp and doesn't have the possibility of injuring the gib stopper when they come.

A tip that Rich gave for long lengths of wall when working on your own, was to measure one part of the wall to a easy measurement eg. 1000mm or 1500mm, then turn tape round and measure up this point (rather than trying to do the whole length).  

For external corners, Rich also went over how to mark this out today for the skotia.  Firstly we had to wait for the slimline to be stopped, this is because it will be covered up by the skotia and the plasterer will only be able to stop up to the skotia (but not the whole length)

Once done, cut off's of skotia are used to lay at each angle and is marked out on the ceiling.

The point where the two lines cross will indicate where the length of the skotia needs to go up to in order to form the join.

This measurement is taken and the length is cut out from a skotia with a mitre cut on edge done so that the two angled skotia pieces will meet.

We also got started on the architraves today as well.  The first step when doing this, is to check that none of the fixings on the gib are protruding out, or expandable foam or packers on the openings frame edge either.

Once all clear, a 3mm quirk can be marked out at each corner, which act as a guide for the architraves to be lined up against (as pictured to the right).

Once the quirk has been marked out, the first length of architrave can be cut out.  This should be the top length, and is a measurement of the width of the opening is taken with a good 100mm additional added to this to allow for cutting out the angles required.

It is a good idea to mark out on the timber the direction that the mitre cut is to go, as because the timber used is a single bevel it means the straight edge has to go against the back fence of the drop saw (which can start making the cut a little confusing).

Once a rough length of timber has been created, one of the angles on the end is cut out and then lined up on the opening to the quirk line, the opposite end can then be marked out on the architrave by matching up with the quirk, and can then be cut out.

Next the lengths can be done, with the same process followed. When attaching these lengths to the already fixed top section, it's edges are glued to provide additional fixings.

The last length to be completed will be the bottom length, with the same steps.  The overall result will be a architrave with beveled edge facing inwards & straight edge outwards, witha  3mm quirk.  

Fixings used are 30mm pins through architrave to jamb, and 40mm pins through architrave to gib using a finishing gun.  These are done in couples in even intervals that are sufficient enough to hold the architrave in place.

It may be necessary to bring the architrave forward so that it is flush with the other fixed lengths of architrave (sometimes the gib may not be flush).  In these cases a chisel is used to prop out the troubling piece until it is siting correctly, and then it is held into place by a panel pin being manually driven in (as pictured right)

For lengths of architrave down the sides of doors, the bottom section will be cut straight to go in line with the floor.  

A quick way to get where this cut should be, a 2.1m length should be cut out with the top mitre cut done so it can sit in flush with the top length.

This piece of timber is then stood upside down and leaned up against the top fixed architrave.  Where the top of this fixed architrave meets the upside down length, is where the cut should be made (as seen on drawn picture to the right).

When trying to work out the quirk for the door area where the hinge is, it is very difficult to get measuring equipment in, however, if the architrave is fixed hard up against the screw, this will allow for the 3mm gap required.