We are slowly but surely getting our house in Suffolk to a point where we can sell it. The most problematic bit had been a short length of corridor between two of the bedrooms – for as many years as I can remember, one side has been crumbly old lime plaster, the other side unfinished drywall on a stud partition. Factor in the ugly, tatty carpet and dodgy looking stains on the ceiling, and we had a minor challenge on our hands.
After a good deal of thought, we decided to strip much of it out and start again. I saw an opportunity to practice a small amount of drywalling and to really work on doing it properly. I am pretty rubbish at wet plastering and have fretted off and on about maybe having to get a professional in to sort out our hundreds of square metres of plaster boarding – when it becomes an issue.
About Drywalling
In England it is still common for plasterboard to be given a skim coat of finishing plaster. We are talking Scotland, so dry walling is taped and jointed, but not skimmed. The joints between boards must be filled and finished cleanly enough so the surface can be painted. Professionals use taping and jointing machines, originally perfected by a company called Ames, so practitioners are often called ‘Ames tapers’. The machines work in stages, firstly laying the tape that seals the gap between boards, with the first layer of jointing compound, then using progressively wider heads to build the jointing compound up to board level. They have rollers and knives that remove surplus jointing compound as the machine head runs up the wall. I aimed to do the equivalent job by hand.
Step 1 – The Studwork
I removed the existing off-cuts of plasterboard from the studwork and pulled out the left over clout nails.
The studwork did not have studs spaced correctly to allow a whole sheet of plasterboard (1200mm wide) to be fixed at both edges. This was easy to fix by adding one new stud. Even better it was a short one, above the doorway in that wall. I screwed the stud in place, at the steading I would probably be using the nail gun.
Step 2 – The Plasterboard
Having acquired three sheets of 12.5mm x 2400 x 1200 bevel-edged board and a box of 1000 35mm bugle-headed drywall screws, I cut the boards to size. I fixed the three sections of board with screws spaced at 20 cm intervals, down the studs and across the noggins. The screws were never less than 10mm in from the edges of the boards.
I had two problems that I need to work on 1) driving the screws in absolutely perpendicular to the board surface and 2) getting the screw heads to countersink below the surface of the board, without breaking the plaster. So I ended up with a few that were slightly wonky and one or two that were not below the level of the boards – these were a pain throughout. A valuable tip is to use a drill/driver and not an impact driver, which is just too brutal on the board. I have since come across drywall screw adaptors which are self-limiting, which I will get as a priority – they have a Philips #2 bit which disengages when the screw is just below the surface of the plasterboard.
Step 3 – Jointing
Next I broke open my bag of GTEC jointing compound and mixed batches in an old litter bin, using my drill mixer attachment. It behaved very well, forming into a perfectly smooth slurry, I can see exactly why in the US it is called mud. The 5kg bag I bought would have done about 5 times the area of board I was sorting out – it really is quite economical.
I used a self-adhesive 50mm mesh tape across the board joints, not the paper tape used by the machines – this was because I happened to have a roll of it kicking around. I am not convinced it makes any difference, I expect the paper is cheaper, but again, a little goes a long way.
With the tape in place, I used a three-inch wallpaper scraper to press jointing compound into the tape, I should have got myself a proper jointing knife but the scraper worked well enough. And the compound was very well behaved, easily forming a smooth flat surface into the bevelled edges of the boards. Any surplus that was squeezed out the sides was easy to lift off and re-use.
After the compound had hardened, but not dried out, I used a 6-inch knife to lay compound on top of the first layer. Again I pressed the compound right into the bevels on the board edges and, as long as I made unhurried single movements, got impeccably smooth finishes. I let it go off properly and used a plasterers flexible hand sanding pad to smooth off the imperfections, mostly at the top and bottom edges and where I had gone from smoothing down from the top edge to smoothing up from the bottom edge. A caution here, I did overdo some of the sanding and roughened the surface of the paper on the board. It is hard to recover from this and it did show through at the finish, even after priming – be sparing with the sanding block. In this case it did not matter because I was papering over the finished board, rather than painting.
For the third and final layer, I used my 12-inch float. I had let the previous layer dry out so I used a plant sprayer to dampen it. Again, provided I made smooth, single movements, I got a very good finish. This layer filled the bevels and brought the compound up to the level of the board. With minimal reworking, I achieved a very good join, so that after a light sanding, I achieved the required standard – I could run my fingers across without feeling any change in level. Mostly, that is: I made the mistake of correcting one defect after the compound had started to go off and made it all much worse. I would have had a slightly easier time if I had had a 14-inch float in place of my 12-inch one, it would have overlapped the width of the bevels by more.
And the wonky screws heads came back to bite me – I had to sand the heads down as best i could, it was not possible to completely disguise them without removing them and starting again.
Step 4 – Finishing
Once I had got the jointing sorted, I treated the whole area with primer. The proper drywall primer comes in 6 litre tins which would have been ridiculous for the few square metres I was working, so I got away with left-over paint primer. It should allow a future owner to easily remove the wallpaper we planned to paste over.
The Outcome
All-in-all, I felt quite smug with myself, for a job well done. I am slow, but am now reasonably confident that we will save a chunk of money and do our own taping and jointing, to a standard where we can paint the finished surface. I did not have to deal with either inwards-facing or outwards-facing corners.
Top Tips
The right tools & materials are essential, in my mind. I would not have got good results without the bevel-edged board, the jointing compound, the mixer attachment for my drill, the three widths of jointing knives/floats and the plasterers sanding block.
Good lighting is really important. I started out working in a gloomy area and once I had lighting in place, I found it much easier to spot imperfections and do something about them.
East Byreleask Steading 