Moisture on ceiling spotlights

Postik

Just chiming in to say those cracks around the wall/ceiling and windows don't look like cause for concern to me.  I had them in my 40 year old house and to a lesser extent have them in my 5 year old new-build.  Decorator's caulk covered most of them although some still did come back over time.

ThisIsWeird

FreshlyCutFlowers said:

ThisIsWeird said:

 But certainly, the gap around the pipe is not intentional ventilation...

Could this be a part of the problem? Should I try to seal it 'properly' ? 
I saw something like this can be used but thought it was very expensive. I also don't know if it will really fit properly as the ceiling is 'angled' and this assumes it is flat.

I love my house except for this room and unfortunately I spend lots of time here in the cold.
I wish I could pay someone trusted to come help fix it up a bit but I don't really even know who would take a job like this. It being 'damp' seems to just be treated as magic and its hard to find someone who knows what to do.

I am not surprised that the extension area is hard to heat - it's long and narrowish, with three sides being external walls. Unless these walls were insulated properly - and I suspect you have no idea if they have - it will always cost a lot to heat it.

Of course, another reason it can be hard to heat is if there isn't sufficient heat being given to it! Do the rads in there get 'hot', and how many are there - and what size, and where located?

You also don't know if there's insulation in the concrete floor.

All in all, I suspect the only solution is to have either the inside or the outside of the walls lined with insulation, but that is obviously going to be very disruptive, and not at all cheap.

The only place where - seemingly - you know there's insulation is the ceiling! Since the guy was a roofer, I think we can assume it's all been done correctly up there! 'Correctly' means that the small void above your ceiling is ventilated freely, so that any moisture that does get through from your house is simply blown away, and doesn't condense inside that void - where it could cause issues. Let's not go there - there is no reason to suspect anything amiss.

The ceiling lights are def cold, tho', so that can be sorted. Bear in mind that this will not make your room any more obviously easy to heat - I fear the 'improvements' will be trivial and immeasurable. (And, it's as likely that the frost was melted by the heat from the lit bulbs as it was from heat escaping your house.)

Ok, bearing in mind what you told us - there are round holes in the ceiling, but the Celotex has been cut square and larger above this, this is what I think I'd do. (I'm MickeyMouse in many ways, but these things should work...)

1) Remove one light fitting (power off, of course) and leave it dangling. Hopefully it has a reasonable amount of cable on it, and hopefully that cable is the usual 1 or 1.5T&E. Check whether the lamp is 240V (mains) or 12V or so (so there's a transformer up there). I suspect it'll be mains.

2) Shine a torch up there, and see if you can make out the cut edge of the Celotex. Also check what thickness the Celo is (that'll tell us how much of a cowboy this roofer was...)

3) Research the fittings you will replace it with. I'd suggest - for sheer convenience - it should be surface-mounted, like the last of the examples shown earlier. Any type that needs sinking into the p'board will increase the fitting complexity by a huge amount - a totally different set of skills (and tools) will be required. Make sure the fitting of your choice is large enough to cover the hole. Make sure the light it gives out is pleasing - it might not be as 'spot'lighty as the existing (no bad thing imo...). In short, I guess this means buying one, and trying it out. This will only need basic electrical skills - not unlike wiring a plug - but you DO need to isolate the power FULLY, and to have a good idea of what you are doing.

4) I'd personally tackle the whole hole issue like this: Straighten the cable as it comes through the hole. Wrap a strip of paper around the cable snugly, and secure with sellotape. Slip this paper sleeve up so that it sits centrallyish in the hole, and extends to just below the ceiling but also extends above the top of the celotex. You want this 'sleeved' cable to be sitting fairly centrally in the hole, so you may need to use masking tape or similar to hold it there - say a strip stuck to the ceiling, crossing the hole, wrapping around the paper sleeve, and continuing past the hole to the other side - that make sense?

5) Carefully, and slowly, aim a bead of expanding foam up towards the top of the Celotex - say an inch below the top surface. Spray a circle all around. If you have decided to replace all the lights, then move on to the next hole.

6) Once partially set, add another bead. By now you should have an idea of how much it expands by, so feel free to 'fill' the hole if you like (by 'fill' I do NOT mean fill it with the spray, but add enough so that it fills the hole once expanded!). You don't want excess going up above the Celo, but it doesn't matter too much if it extends down beyond the ceiling - that can be cut off with a craft knife afterwards. The stuff can 'slump' if you add too much in one go - and you don't want dollops of this on your floor...

7) Once set, use a craft knife if needed to remove any sticking down beyond the ceiling - do NOT nick the cable... If the foam hasn't fully filled the hole - if there's a half-inch recess there - that's fine. Your call whether to bother filling it fully.

8) Once set, the cable should be able to be slipped up and pulled down. Fit your new light. Don't bother using screw plugs - just screw directly into the p'board, pressing firmly so the thread cuts in nicely. That will be plenty to hold it. You could even use double-sided sticky pads, but I'd cut them into small strips - say 6mm wide - and just use a couple. That'll still hold the light, but won't cause too much paint pull-off if you need to remove them.

ThisIsWeird

The Flue Pipe. Since the ceiling is on a slope, then a simple round collar might struggle, as you suspect.

So, same idea: wrap a sleeve of paper around it snugly, and slip it up to the top of the hole in the p'board. Then use a general purpose filler to start filling up that damage. You have a flat ceiling surface all around the pipe to use as your guide for the filling blade, so get some filler up there, push it firmly in against the exposed p'board edges, and let set. Add more, until you are getting close to the ceiling surface. Let set. Then add enough to complete the fill. Run the blade all around to level it off. Once set, it'll likely need a further thin skim.

Let fully dry, and then sand flat.

Carefully trim away the exposed paper.

Bear in mind that these two jobs will not noticeably help to warm your room.

ThisIsWeird

FreshlyCutFlowers said:

The windows were free from condensation

It's a very shallow void. The celotex holes are square and bigger than the holes so getting new celotex in wouldnt be doable from within the house I think. I think I'd have to open it up somehow.
The lights: I dont have a lot of money spare so I hadnt intended to change anything unless its for a practical reason. This is a reason I am willing to change for.

Interesting that the windows are clear. Hopefully it's because they are decent double-glazed items, and not because they are so leaky that they kept themselves dry!

No, you ain't going up into that void - that is major work, mess and hassle. You'd only do that if you really needed to. Hopefully you'll be able to tell us how thick that Celotex is as asked in my earlier post. If it's 'thin' - 2" or less - then the solution would be - I'd suggest - to add a further inch or two to the underside of the ceiling. Having said that, 2" wouldn't be too bad, but is well under current regs.

It's a toughie, and it may be that you need to try different solutions in order to keep the room as dry as possible. For instance, you can keep the heat on in there 24 hours, and that should help, but you know how much that'll cost you...

Instead, the way to prevent overnight cond is to ventilate the room thoroughly. You could turn off the heating in there, open the windows fully, and wake up to a bleedin' freezing room - but it would be dry. I'm not suggesting that extreme, but what I would do is to keep the overnight heat at a 'protection' level - say 8oC - and shut all the doors between that extension and the rest of the house. Then crack open every window in there to 'vent' - ~ a lockable half-inch open.

First thing in the morn, after you've made a cuppa, close all the windows, and turn the heat up to 16oC. It'll clearly take a good while to reach that in winter, but at least it's useful heating, and not being needlessly lost. If you can see it's going to be a sunny day, and if sun does hit these skylights, then you may even wish to hold off until it does, and use solar again to get the first 5o rise going on.

In short, you heat a room only when you actually need to. And you ventilate it overnight.

As for the lights, there is no 'need' to replace them if you don't want to. It would be 'nice' to sort the lack of insul issue above them, but it's not a hugey in the scheme of things. Perhaps do your research and look at some suitable lights - do you have a CEF or similar nearby? Explain you are after LED surface-mounted, as similar to downlighters as poss? If you can then find them at an acceptable price, use that to make your decision for you :-) Keep an eye on eBay and your local Fb - bargains always to be had if you look for long enough.

grumbler

FreshlyCutFlowers said:

grumbler said:

What I suggested can be done at any season and doesn't require opening the roof.

I appreciate your messages a lot, thank you.
I am crossing my fingers that I am missing something: How would I go about filling up the void with insulation like celotex? The only access I have is the tiny down light. The void between my ceiling and the tiles is very small, it is not a 'loft space' with room for a person and there is no access into it from inside.

I didn't suggest celotex. I'd possibly use expanding foam or just mineral wool,

ThisIsWeird

FreshlyCutFlowers said:

I also had a person in to look at this wall but he said it was not to do with any of this and was likely just plaster contracting due me letting the room get too cold (10 degrees)

Hadnt included any of this as I was assured it wasnt a big issue, but maybe this is all damp? 

I don't think there's anything unusual going on there; they are pretty typical of hairline cracks you'll get over time. Yes, it can be exacerbated by large temp swings, but we're all going to be getting these at one time or another - above 30oC was not uncommon for many over the past summer (I said 'past' :-(   )

It will also likely be made worse if there is damp - say the room isn't ventilated enough, so the warm moist air from the rest of the house condenses out on the walls rather than being ventilated away. The walls may well be cold, but shouldn't feel 'damp' - do they?

I'd personally tackle all these the same way - apart from the window surround, for which flexible caulk would likely be best. I wouldn't use caulk for the rest, as it cannot be sanded, and almost always looks a mess - it dries really quickly and leaves a surrounding skin that paint won't hide.

My method (not at all guaranteed, because it's hard to know just how much continuous movement there will be) is to first sand the cracks to remove all loose bits, and to expose the plaster below. Run a vacuum brush over it to remove all the dust and to try and clear out the cracks.

Then get some SBR (a waterproof building adhesive - good stuff, cheap too) and use a brush to liberally get as much into these cracks as possible. Brush across and long the cracks to force it in. Observe - is it being sucked in? Cool! Keep going, until that sucky stops.

The use a damp cloth to wipe away any left on the painted surface.

Allow to fully dry.

Get some 'fine' 'flexible' 'surface' filler, and a filling knife. Force it right in to the cracks, and then run the blade along the crack to level it off. Don't worry about getting it perfect - chances are it'll shrink a small amount anyway. Once dry, sand using 120 grit on a flat block. Wipe clean. Add another smear of filler if needed. Sand.

For the window surround, use a craft knife running flat along the two surfaces to cut into and lift away the old caulking. Sand each edge to get them flat - no raised bits. Vacuum. Brush in SBR. Let dry. Caulk (see YouTube vids, and follow the instructions.)

This is all cosmetic, of course, but very worthwhile. 

If in any doubt about cond, then perhaps repaint using bathroom paint - but not shiny stuff :-) 

Chickereeeee

grumbler said:

FreshlyCutFlowers said:

grumbler said:

What I suggested can be done at any season and doesn't require opening the roof.

I appreciate your messages a lot, thank you.
I am crossing my fingers that I am missing something: How would I go about filling up the void with insulation like celotex? The only access I have is the tiny down light. The void between my ceiling and the tiles is very small, it is not a 'loft space' with room for a person and there is no access into it from inside.

I didn't suggest celotex. I'd possibly use expanding foam or just mineral wool,

Celotex would be a pain to fit accurately - you would certainly have gaps.
It is not great using expanding foam overhead, and it should not come into contact with pvc coated wiring.
Mineral wool would be my choice. Ideally Rockwool, but failing that, glass fibre. Stuff it in the  hole until the void is full. Not quite as thermally efficient as celotex in theory, but better in practice as there will be no gaps, and much easier to fit.

ThisIsWeird

Wool is a good call, but I'd still go with sleeving the cable to protect it - and allow it to pull through and back afterwards - and spray foam. Once filled, it won't dislodge. And insulation value should be good.