Fitting downlights dilemma – fit from below or above?

[JackReacher]

Recently moved house and looking to get some LED downlights fitted to ground floor study, and part of the hallway. I understand the best way is usually to come in from above. Why is this considered the best way? The floor upstairs is large sheets of chipboard which have been glued and nailed down. I understand this is going to be difficult to lift up, and carries risk of cutting into electrics/plumbing.

The alternative seems to be coming up from below, but involves taking down the ceiling, getting the electrics in place and then new plasterboard and skimming. House is 16 years old if it makes any difference.

All rooms need to be decorated with new flooring anyway, so I don’t mind a bit of mess either way, but I’d prefer the easier (and therefore more cost effective option) with less risk of going into some plumbing/electrics.

[JackReacher]

anonymous said:

[redacted]

Thanks, yes the issue is the wiring I presume. As far as I can tell it's lift the chipboard up (although this may be tricky as some it runs under stud walls, or take ceiling down and run wiring through the joists. Not sure which way the joists run, but was told once they tend to run opposite direction to those in the loft? Access should be ok in terms of both rooms will be empty.

[Risotto]

I'm not sure how things work with sheet flooring but with traditional floorboards it's usually a case of using a floorboard saw or circular saw to cut across the board above the mid point of the joist. You then cut through the tongue along the long edges.

Finding the joists should be simple enough - all the visible fixings will penetrate the joists so wherever you can see nails/screws, there will be joists below. If you discover your cut doesn't leave a great deal of the board supported by the joist, just add a suitably sized piece of timber to the side of the joist to provide additional support when refitting the board.

Taking up entire boards isn't necessary and would still require cuts to be made as I imagine they use some sort of tongue & groove system to lock the boards together.

Assuming your first floor is carpeted then covering the cut boards is simply a matter of refitting the carpet. Taking ground floor ceilings apart is going to require a lot more remedial work.

In terms of avoiding cutting pipes/wires, just take care when setting the depth of the saw cut - i.e. only use the minimum depth necessary to cut through the flooring.

Edited by Risotto on Monday 24th October 15:58

[sparkythecat]

Risotto said:

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In terms of avoiding cutting pipes/wires, just take care when setting the depth of the saw cut - i.e. only use the minimum depth decessary to cut through the flooring.

And as a precautionary measure, make sure that you know how to turn off the water and drain down your central heating system as quickly as possible. Have all the tools and hoses necessary to do this immediately to hand, in case you balls it up. Reward yourself with a celebratory treat and claim 10 man points if you find that you don't have to use them.

[V8RX7]

The sparky will set his circ. saw to 18mm and cut through the boards (then 22mm if he's not through it)

This way 99.99% of the time he won't cut through any plumbing / elec

He will either remove the screws or sacrifice the blade and cut down the joists or just go where he wants and bridge underneath with CLS then screw the offcut down onto that.

[Bristol spark]

Its possible to do from below, without bringing the whole ceiling down.

Its a case of cutting lots of 80mm holes in the ceiling for access, and for drilling through joists etc.

Then glue/screw the cutouts back in. Then get ceiling skimmed.

Its still messy, but not as messy and expensive of new ceiling.

[gtidriver]

Have a look for super rod, I've put lights in using these and the super long drill bit. Watch the videos on there site. Can get expensive,ive spent probably £400.

[miniman]

Sparky fitted 4x downlighters to my dining room from below with a couple of small holes to the plasterboard, otherwise no damage.

[MrChips]

Bristol spark said:

Its possible to do from below, without bringing the whole ceiling down.

Its a case of cutting lots of 80mm holes in the ceiling for access, and for drilling through joists etc.

Then glue/screw the cutouts back in. Then get ceiling skimmed.

Its still messy, but not as messy and expensive of new ceiling.

We recently did this in our living room as had tongue and groove boards above which would have been a pain.

Apart from the fact that filling and sanding the holes has generated more dust than I'd hoped, this certainly seemed to be a good solution.
We did the holes only down one wall, then ran the cables across the width of the room and back for each downlight.

[JackReacher]

Thanks all, seems like both methods are a viable option. Setting a saw to the depth of the chipboard should stop cutting anything important which is a good idea. Think I should probably get some expert advice both on installing and the position of the lights.

The other issue is that the current floor is incredibly squeaky. I could see this going either way, taking them up might make it worse after going back down, or might actually make it better if laid more firmly with better fixing.

[Belle427]

I've cut access panels from above using a fair sized holesaw before, easy to use the piece to just screw back in with a few batons.
Takes a bit of planning and care but easier than repairing a ceiling.