As the popularity of under-floor heating increases we are
inevitably seeing a larger number of faulty installations.
This is the way of the building industry but it needn’t be
so. Plumbers are often called in to pipe up under floor
heating manifolds to the heating systems after the floor
loops have been laid by others.
Because it is trapped, the pipe expansion will take place within the walls of the pipe rather than along it...
Laying pipes into screeded floors might seem like a job for the labourer (beneath plumbers’ dignity) but entrusting this job to someone who doesn’t have the background knowledge is where mistakes are made and hidden until a future date when the pipes fail. The whole system might stand up to a pressure test and be assumed to be fine but when laying heating pipe under screed you need to keep in mind that:
Condensing boilers have undoubtedly become more reliable
over the last few years but the last couple of winters saw
thousands of householders caught out by frozen condensate.
Manufacturers offer clear guidelines for avoiding freezing
but not every job offers the opportunity to do things by the
book and terminate the condensate inside the building. If
the pipe runs to an outside drain then there is always a
chance that it will freeze. In response to this we now have
a number of products on offer which will stop condensate
pipes from freezing. Invariably these use electric trace
heating (electric blanket) for the pipe. An average cost for
fitting trace heating is around £200.
...installers are being advised to redouble their efforts to find somewhere inside the building to terminate the condensate.
The question is who pays? If you’ve had a boiler fitted in the last few years and have suffered a breakdown due to the condensate freezing, you might reasonably expect the person who installed it to carry out the remedial action free of charge on the grounds that the boiler was not fit for purpose. However, it seems that many installers are arguing the point saying that practice of lagging the pipe should have been enough under normal circumstances to prevent freezing and the only reason the pipes are now freezing is abnormal weather. In other words the boiler will work fine so long as it doesn't get very cold. Some would say that this misses the point.
The quick fix offered by many installers and manufacturers last winter was to take a kettle of hot water and pour it over the condensate pipe. It's a very British solution to, ‘put kettle on’ and the site of people out in their dressing gowns at 6am with steaming kettles has a kind of pathetic charm.
In the longer term installers are being advised to redouble their efforts to find somewhere inside the building to terminate the condensate. Ideally this will be a soil stack or waste pipe from a kitchen sink but I give full marks to a heating installer I came across the other week who found a handy soil and vent pipe close by to put his condensate into. He drilled a hole and fitted a strap on boss (sounds pornographic if you aren't a plumber) and left the boiler in good working order.
A few hours later the householder called to say that there was dripping coming through the ceiling. The installer, being a psychic, said he knew the cause without even coming back to the house. It was the WC upstairs which was leaking. The householder found it strange that this should happen at the very time the boiler was fitted and the dripping had stopped since he switched off the boiler but the installer insisted that it was nothing to do with him and told the householder that coincidences must happen otherwise there would be no such word as ‘coincidence’. Not only was it nothing to do with him but he wasn't interested in fixing the problem because he was a heating installer and not a plumber. He hadn’t spent thousands of pounds gaining his gas safety certificates just to end up messing about with bogs.
So it came down to me, a lowly jobbing plumber, no job too small. It took me less than five minutes to track down the leak. It wasn't coming from the WC at all; it was dripping out of the ceiling fan.
The reason it was dripping out of the ceiling fan was that the installer had terminated the condensate into a length of grey plastic soil pipe that he took to be the vent section of the soil and vent pipe. It was infact the vent duct from the extractor fan. Mistakes happen and I wouldn't judge him too harshly on this one except for the fact that he still wasn’t putting his hands up to the error. He had taken the pipe to be a soil pipe in good faith when he had put in the estimate and the fact that it wasn't meant that he now had to run the condensate pipe some considerable distance to pick up the said soil pipe. Suddenly he was the aggrieved party.
The householder was faced with a bill for another £200 to do the job properly, or he could poke it out of the wall and take responsibility for it freezing. But if it did freeze all he would need is a kettle full of hot water.
Because it is trapped, the pipe expansion will take place within the walls of the pipe rather than along it but where the pipe leaves the cement screed and enters free air is a critical point. Suddenly it is able to expand and contract freely along its length but the point of transition is susceptible to abrasion. It must be sleeved at this point either with plastic conduit or pipe insulation to prevent this happening. If this isn’t done there is a risk of leaks occurring. The other vulnerable point in under screed pipes is the thresholds between rooms. The screeds between rooms always crack at this point and this is a wholly good thing because it allows each room to act independently. It does however mean that the pipe at that point will move minutely and, again, abrasion can wear the pipes. This will also happen where pipes go through walls.
Pipe failure could be 10 or 15 years from now, and whilst plumbers and builders will be free of their warranty obligations by then, it is not a long time in the life of a building, or perhaps I am out of step by thinking that pipe which is guaranteed for anything from 25 to 50 years ought to actually last that long in a building as well as a laboratory.
The golden rule that I have followed through years of fault
finding is 'never assume and never jump to conclusions'. OK
that is two golden rules but the basic message is never say
you know something until you prove it. This has stood me in
good stead where other tradesmen have come and gone from a
job missing one small fact that changed everything. This is
not superior wisdom just hard won experience from getting it
wrong. And sometimes I still get it wrong as this job
I had been called out to look at a leak around the bath. It is almost always due to a defective silicone seal but I didn’t just assume that. I checked it by spraying water all around the edge of the bath. Sure enough the water poured down. Positive proof!
The leak had been going for some while and made a real mess. We got the job to take the bath out and renew the rotten chipboard floor and cover the walls with Knauf Aquapanel before re-tiling. This was the fourth flat in the block to suffer from these problems and it had caused bad feelings among the owners so this customer didn’t want any further trouble from his bathroom.
He didn’t mind paying for a good job but he wanted a guarantee. Now I know there are some plumbers who would not put their name on a piece of paper that says 'this won't leak' but I was 100% confident.
Firstly we were going to renew the floor, and then we were going to get rid of the plasterboard at the shower end and put up some tile backer board. We were also going to beef up the stud work to prevent any movement. Then we were going to tile the floor under the bath so the tiles came right up to the wall. The Ardex shower waterproofing system would then be used to make a damp proof membrane that ran down the walls behind the bath and onto the floor so any leak would not be able to seep down under the floor.
There would be a silicone seal between the bath and the wall and then another silicone seal after the wall had been tiled. It was near enough a week’s work to do this but I told the customer that I was sure after all that it wouldn’t leak, but if it ever did (which I doubted) he would know about it because the water would seep out from under the bath panel and appear as a puddle on the tiled floor. This might seem like belt and braces but it is actually standard practice on the Continent, we are almost alone in ending the tiles just under the bath panel.
We obviously tested the bath waste and even replaced the flexi tap connectors just for good measure. I have heard too many horror stories about flexis springing a leak and would never use them in a flat. We finished on Friday lunchtime and everything looked good. That weekend I received a text saying that a puddle had appeared on the bathroom floor.
It was Sunday morning but I went straight over. The leak appeared to be coming from the bath waste so I took it apart. There were traces of Plumber’s Mait on the underside of the waste which indicated that this had been a previous problem which someone had tried to fix. We had obviously disturbed a bad repair. Plumber's Mait is not suitable for bedding in wastes of any sort but thousands of people use it for this job every year. If you ask Evo-Stik, the manufacturers, they will verify that it is unsuitable for wastes. If you need a sealant for wastes then silicone is much better.
I removed all of the Plumber's Mait and, because the rubber seals looked fine left them to do the job they were designed to do. I ran the bath and it looked OK. Monday morning I got another text 'Bath still leaking, please fix today'. This time I decided to renew the whole pop up waste assembly. It looked fine. Monday night text number three 'still leaking, pissed off'. Looking on the positive side at least the idea of tiling up to the wall and sealing the wall to floor joint had paid off with an early warning of what was really a small leak. If we hadn’t done this then the people in the flat below would have been the first to know.
I went back to the bathroom and after half an hour of having the bath full of water and nothing coming out I wondered if the problem was more to do with the person using the bath than the bath itself. He was a big guy and I wondered what difference it would make if you had another 110kg in the bath. It all seemed solid but would things start flexing? My problem was how to simulate this. I certainly didn’t want him sitting in the bath while I crawled about with a torch even if he was willing. It would take a month of Sundays to get that image out of my head. I lay there, head on the floor, deep in thought. It was at this point that the torch light caught a single silver drop of water. It wasn’t coming from the waste; it was coming from the glass fibre of the bath. I pushed it with my finger and a few more drops came down. I discovered that the bath was spongy. I could actually push a blister of water around. Clearly it had leaked through the acrylic top and been trapped by the reinforcing coat of glass fibre. I shone the torch down through the water and there it was, a hairline crack. The one thing I hadn’t proved at the outset was that the bath was watertight. Because 95% of leaks on baths turn out to be from around the silicone seal I had jumped to the conclusion that it was the cause and I hadn’t looked at a secondary cause.
The task now was to remove the damaged bath (easy with a recip saw) and then fit a new bath without damaging all those lovely new tiles or the new bath. That was slightly trickier because it was a snug fit. The customer, obviously not expecting to lose weight any time soon, decided to go for a steel bath. Good choice in his case. When we cut that old bath in half you could see the weak spot. It was all along the edge of the chipboard reinforcing panel where the inner acrylic joined the outer glass fibre. There was a triangular void all the way along both edges. It was inevitable that it would fail fat bloke or not, but the fact that the percentage of obese people in Britain has now reached epidemic proportions means that plumbers will be busier with this kind of work.
At the time of writing there is a blizzard blowing outside
my window yet only last week I cycled along the Brighton
seafront in a tshirt and shorts. It just goes to show how
difficult it is to predict the weather in these islands of
ours. Most of us have our heating on a timer and because of
this unpredictability in the weather the time it takes for
the house to heat up can vary.
From day to day you can come downstairs to a house that is either icy cold or too hot. There may even be days around the changing of the season where the heating comes on when it isn’t really needed. Money down the drain before you even start your day. Ideally of course we would have our heating controlled by a smart phone app that logged into the Met Office to give us a prediction of temperatures for our postcode. As far as I know that isn’t yet available but watch this space. What is already available is a device called an optimiser that senses the outside temperature and compares it to the temperatures in your home over the last few weeks. If, for example, it is 8 degs centigrade in the garden and your optimiser knows that over the last few weeks it has taken your house 1 hour to reach full temperature at 5 degrees outside then the device will work out that your heating system will only need 40 minutes to reach the desired temperature so it delays the start of the heating. It may sound like a small saving but add it up and you have a significant saving. The biggest benefits are to be had around the seasonal changes but, as I have already indicated the most predictable thing about our weather is the unpredictability and changes can occur even in mid winter. The ability to talk about that fact day in day out and still find it novel and fascinating defines Brutishness’ better than anything I know.
Modern high efficiency boilers aka condensing boilers can
save you a fortune on fuel bills compared to the old
fashioned non-condensing type but the condensate that drips
out of a little plastic pipe into a drain can freeze up when
temperatures drop. So just when you need your boiler most it
lets you down, causing you to fall a little out of love with
it especially if the plumbing bill is more than the savings
you have made on fuel bills. Well before you reach for the
phone see if you can trace where the little white plastic
pipe that comes out of the bottom of your boiler goes to. If
you see it going through the wall and you can follow it to
its end you may find a solid ice plug sitting there.
Take a kettle full of hot (not boiling) water and pour it onto the pipe. You only need to do this on the external section. If after a minute or two you see a gush of water coming out of the pipe you have solved the problem, at least for now. You may have to press a reset button on the boiler or switch it off and on again to fire it up. Now I don’t know you but I am guessing that you don’t want to go on kettle patrol every time the temperature drops below freezing so you need to seek a better long-term fix. There are a number of devices on the market that can help solve this problem for good and, for the most part, they are simple to fit. A good plumber will be able to advise you on which is best for your installation and should be able to fit it fairly quickly but you may want to chose a time when they aren’t run off their feet fixing this problem for all the people who haven’t learned the little trick with the kettle. Keep warm. Roger Bisby
It never ceases to amaze me how many people in this country
still don’t have loft insulation or if they do they have the
absolute minimum . You would think that everyone would
understand that insulation in a roof space will keep the
house warmer but still some people don’t quite believe that
it does what it claims to do.
Nobody in their right mind would go out in the snow without a good coat or jacket ( Ok you can’t include kids in this because they are controlled by fashion which is something much more powerful than the need to stay warm and even if you send them off to school wrapped up in a nice new winter coat they will ditch it as soon as they get around the corner because non of their friends wear coats) but I am assuming that once you become an adult you do not consider it cool to be cold. So why are some people still in denial about wrapping up their homes against the cold?
It isn’t even as though it costs money, there are lots of subsidies available for insulation and even if you don’t qualify for any of them the cost of the insulation from your local DIY store is often so cheap that you will recover the cost in one season alone. But it isn’t all about saving money or even the planet, the one thing that many people forget to mention when extolling the virtues of insulation is the happiness factor.
Thermal comfort isn’t so much about raising temperatures as eliminating cold spots. If you do that and cut out the draughts you can often turn the thermostat down a degree or two and still feel just as warm.