Best way to (re)board (re)plaster ceiling prone to cracking?

[kgk]

Hello plasterers!

The plaster ceiling in our upstairs hallway will always be prone to cracking due to the unfortunate structural flex in the area from the loft access. There is no real practical option at the moment to change / strengthen the beams.

The ceiling was reboarded and skimmed three years ago. The boards were fixed with galvanised clouts and have been prone to nail pops, but most of those have slowly been repaired (nail pulled) with drywall screws added to either side.

The flex is (or at least was) enough to have cracked the plaster at the board seams, along the taped joins. However, the flex is not (now) enough to be (easily) noticible from below.

I have the opportunty to have the ceiling reskimmed and am looking for advice on how to keep the crack from opening up this time.

The plasterer is a family friend, who is a retired general builder. He volunteered to do the skimming, but also offered that he really wasn't sure what to do other than retape the joint or possibly double board. Double boarding, with another layer of plasterboard with different join lines would be a fair amount of work and I can only guess at its effectiveness.

For less dramatic approaches, I seem to recall that using multiple tape lines and feathering extra wide across the board joints may help. I also vaguely remember mentions of flexible ceiling coatings. Hopefully you experienced DIY'ers and professionals have some solid approaches.

Thank you for reading, considering the problem and sharing your experience and advice!

 

[ree]

Why is it not possible to access and strengthen the ceiling joists? If the loft joists are exposed its simplicity itself to re-arrange them.

If the loft access hatch is located over a stairwell, then now would be the time to change its position.

What you are proposing would entail a whole lot of work for not much promise of success.

If the original ceiling is plaster lath pinned to very shallow section joists (typical for older houses) then more weight will mean more sag.

 

[kgk]

ree, thank you for reading, considering the issue and offering your advice. I appreciate (and am a believer) that fixing the root cause of a problem is often the best way to go. However, that is not always an available or truly practical option.

The house is approximately 100 years old and has been in the process of a complete gut and refit. That included the removal of the old plaster and lathe, and (as noted in my post) the ceiling was re-boarded a few years ago. At that time it might have been barely practical to sister or replace the existing ceiling beams, but there was not known to be an issue in the area.

That said, the spans for the beams are (now) very limited (2800mm length, 400mm centers, 2200 width, 100mm x 50mm actual dim original seasoned timber). The supporting wooden lintels have been replaced with reinforced concrete lintels as part of other structural works and all beams resin floated for contact. In addition, a new lintel was added to achieve this shorter 2800mm span. The beams could easily support the weight of double boarding. The problem is that -- with the construction of this purely interior stairwell -- they are not structurally restrained at the ends and can flex and twist. Yes, noggins would have been advised to help as a fit from below palliative, but the problem was not known at the time. For now, all that can be done at this time has been done.

Accepting the limitations of the existing situation, I am still wondering if anyone has a suggestion on how to allow for a bit of extra flex in the skimmed plasterboard joint.

 

[ree]

Are you saying that there is now a fixed staircase running up into the loft?

 

[kgk]

No, there is not a staircase running up to the loft. It is just a ceiling with a loft access hatch leading to a boarded area, rather a standard configuration in English/British houses. But, in this specific case, that area and the roof and services configurations are such that access from above is non trivial.

The spans are already much stronger than they used to be owing to works that have been done below (having dropped about 2000mm in span by addition of a new lintel as part of reconfiguring the floor below). Hence, it is entirely possible that a reskimmed ceiling might not crack again.

However, I am still interested in what options may be available (if any) for a fit from below option to make the plasterboard taped joint more resilient to a bit of flex. My interest is at the moment for this specific instance. But a potential solution is likely to have applications elsewhere in the future. This is a very very common problem in British homes.