kitchen - pipes - condensation

[steeley]

Hullo. I am confused about lagging pipes / boxing them in. The main problem is in the kitchen where the water pipes run along the outside walls. The kitchen units did not allow for this but I cut a half circle channel to allow the units to sit against the wall. Good plan or not? Do I insulate (with foam padding) both hot and cold water pipes or box them in or both? Will this prevent condensation from collecting underneath the base units? Also, the cold water mains, right in the corner and pretty inaccessible when units are in place; can I insulate this in the same way? The condensation is so bad here it causes puddles on the floor. The floor is concrete - is there any way water can be coming up through the floor?

Thanks - any help much appreciated.

 

[^woody^]

Insulate both pipes with the proprietary foam tube, and you can get something similar for the mains stop tap.

Remember to mitre the foam at any sharp bends and not try and bend the foam

 

[JohnD]

condensation is usually caused by insufficient ventilation

//www.diynot.com/wiki/building:condensation_in_houses

 

[^woody^]

No amount of ventilation is going to prevent condensation on cold water pipes

 

[steeley]

Hi Woody and JohnD
Thanks for your advice and sorry for the delay - been internet-less for a couple of weeks.
I have insulated the hot and cold water pipes with the foam insulation. Will need to insulate the old connections for the washing machine or ask a plumber to remove??
View media item 6173The wooden backboard is painted in gloss as were the walls and ceiling when I moved in!!?? - why? Is the function of the board to carry the pipes? I have noticed water droplets collecting on this after the insulation was put on thus the condensation is still dripping onto the floor - I am guessing that the mould dots seen on the wall below the pipe run (and on the underside of the kitchen units) are through splashes as the drops hit the concrete floor?? These aren't easy to see on the photos but are there. Will I also box in in addition to the insulation? Will this just allow the drops to pool inside the box rather than fix the problem?
View media item 6174 View media item 6176 View media item 6177The cold water mains - is it ok to insulate this in the same way?? You suggest insualting the tap (special fitting??) but the pipe itself? View media item 6175 Though it is obvious this area is a problem for pooling.
Do I need to insulate all the pipes including the vertical ones that go up to/down from the loft and tanks? and also the pipes serving the sink and washing machine. Seen in the picture with the tap shown. The vertical ones will be inside a wall cupboard; the sink ones etc are inside the base unit shown. Will I insulate and box in?

There is a smell of damp - which alerted to me to the problem. I am concerned that the insulation is not sufficient, the wall is damp and that the problem will persist?? I'm already going to replace a couple of units as they have retained the damp smell (usual melamine faced chipboard)

I'm ensuring that the cooker fan is being used and the window is also open when cooking or washing up.

Thanks again and in advance
Steeley

 

[regsmyth]

It seems a bit odd that you should be getting so much condensation, even though you've now lagged it. I always thought that cold water coming out of the ground didn't get particularly cold, and lagging the cold pipe should be sufficient. It's when it sits in a copper pipe in a loft in winter that it gets really really cold.
Anyway, you will only get condensation if there's humidity in the air - why is the air behind/under your units so humid? perhaps the hot pipe dries out the damp patches, loading the air with water, to condense again on the cold and so on.
If your walls are also damp, I'm sure the hot will do a similar thing, even with lagging. Is the floor also properly damp proofed?
You can also get much thicker lagging, but it doesn't look like you'd be able to fit it unless you re-routed the pipework.

 

[steeley]

hi regsmyth

thank you. I think the problem is lessened now but I am still concerned. I will try to lag all the exposed pipe and then box them in - will this suffice?
The problem has been worsened I think due to people not being home very often and thus no central heating. Also the kettle being boiled a great deal and creating a humid environment in a cold house??
I think the floor is ok - it is solid concrete but the rest of that end (and the whole house) is timber with a large crawl space underneath. As far as I am aware the dpc? is intact. I had a survey done a few years ago and it was all fine. How would I know if it had broken? thanks

 

[regsmyth]

Steeley,
You should try to lag every part of the pipework. Clearly if the house is cold most of the time, there will be a lot of dampness in unventilated corners etc.
It seems some of the pipework may be very awkward to access esp the bit under the unit. Maybe you could use aerosol foam to fill the area, but it'll make future access/inspection difficult.
I wonder if your walls are not well insulated, hence a lot of condensation on them. The heat from the hot pipe could evaporate a lot of it, but as soon as the air cools again - condensation on the coldest bits.
If you lag your pipes properly and thoroughly, and it might be best to use the thick walled pipe insulation (about £1/m from B&Q), I think you should be able to avoid condensation on them. But you will still most likely have a cold and damp wall.
There isn't an easy way to check your floor dpm, but it goes without saying that where a pipe comes up through the floor, the dpm will have been breached. Generally not likely to be a problem, unless there is some real dampness down there, like a leaky drain for example. If you do your lagging properly, and there still seems to be a significant damp problem, then perhaps there is something worse going on.

 

[steeley]

hi reg

thank you - all very useful and must admit I am concerned there is something more serious going on. However, I think lagging the pipes and insulating as youhave suggested will hopefully rectify the problem at least in some part. The house had been filled with cavity wall insulation prior to my moving in but I do believe that it was not carried out properly - under the window sills there is hardly any material and thus likely that other areas in the wall are patchy. I don't know if it worth getting this done again? All the external walls are substantially colder than others. I like the idea of the foam insulation - wondered about putting blanket insulation under the units but worried about ventilation?????
The concrete floor in there is always freezing - guess this is the nature of it? Have not put floor covering in there yet but have tiles - the cold will just come through the tiles though huh?

Thanks again