anyone had any experience renewing all or part of a central heating
system with pipes buried in the concrete floor of a 1960s (bungalow)
building with parquet floor?
As part of our extension plans we will really need to renew the central
heating. The radiators are rubbish anyway. I'm trying to minimise the
amount of work needed on walls and floors in rooms not directly
associated with the extension but with buried pipes there simply has to
be some digging up.
I'd just be interested hear of any horrible experiences of doing
something similar. Did you fill the entire universe with dust? Was it
easy to get the parquet relaid well? Was it all worth it?
Before anyone asks: no, we won't put up with vertical pipes dropping
down (whether boxed in or not) willy-nilly around the house. There are a
couple of places where the drops can be placed sensibly and out of the
way (cloakroom, and behind the dining room door, for example), but still
a small area of floor in the hall and corners of the living room would
need to be lifted to lay new pipes to get to the radiator positions and
the the drops.
Michael Kilpatrick coughed up some electrons that declared:
Would that be "real" parquet - or the 1/4" stick on tiles?
Do you want to reuse the tiles?
The latter can be got up gracefully (mostly) with a sharp bolster chisel,
preferably in an SDS drill - if you're lucky, they pop off without damage,
having just stripped some.
If you don't want to reuse the tiles, then a sharp spade knocks them off
I don't know about "real" parquet - as in thick blocks bedded on pitch -
that might be interesting, especially as you'll probably want to save them
If your floor is precious, I think you might find it easier to chase the
walls and bury the pipes in the wall - it's not so bad if you use 10mm or
even 8mm pipe for the drops, even if it goes to 15mm or 22mm in the
ceiling - a wall chaser with a vacuum attached isn't too bad on a good day.
As to the concrete under the floor - you are either going to have to break
it out (kango time), and damage your dampm proof membrane if you have one,
then make it good or cut out slots with a disc then chase: the latter will
fill the known galaxy with dust.
Let us have some more details and there might be some better answers :)
It's "real" as far as I can see, and there is a thin layer of pitch
beneath it. There are a couple around the edge of the living room that
are damaged and no longer adhering to the pitch. Someone placed a carpet
over the top of it some years ago and we removed it only last year. The
morons just banged the carpet edging skipe-strip into the parquet and
also stapled the carpet underlay, so I had to remove carefully the
staples and nails.
The parquet is a typical herring bone pattern but around the edges has
two runs of square-on blocks. It seems to me that it might be possible
to attack the floor after only removing the two runs of edging blocks
without harming the integrity of the herring bone (assuming most of the
blocks near the edge are still stuck to the pitch).
The hallway is a T shape. Fortunately, across the junction of the "T" is
exactly where some new pipes could be layed and again at this point
there is a double run of square-on blocks that separate the herring bone
areas of the two sections of the hallway - so again it may be possible
only to dig up those blocks, not the herring bone.
I suspect repairing and re-laying the parquet is not the biggest issue.
well, surely the existing pipes aren't *too* close to the membrane, are
Michael Kilpatrick coughed up some electrons that declared:
Ah - that's what I understand by "real"...
There's always one :(
I just wonder how hard it will be to unstick the blocks.
Relaying should be easy - it's the getting it up undamaged that may be hard.
Believe me - having watched builders on my floor, it is possible to cause
widespread damage kangoing up concrete.
However... If your floor is like mine (1950's bungalow), you may have 4"
concrete and 1-2" of screed on top (screed is normal, but there are no
guarantees with these things). There will most likely be either be no DPM,
a DPM sheet under the concrete or a bitumin type DPM painted on the
concrete under the screed.
*If* you can bury the pipes in whatever depth of screed you have, you might
be able to get that out with less damage. But, when I took some of my
quarry tiles off and cut out the screed, it broke the screed-concrete bond
for several inches sideways in places (ie you might loosen the good bits of
 You'll want to sleeve the pipes to prevent copper corrosion if
applicable - and more importantly, to allow the pipe to expand and move
If you can slot the screed with a disc cutter, it might chase out with
minimal damage and less vibration. Or an SDS with a chasing chisel might
work, assuming the screed's not too hard (mine varies between medium hard
and mostly sand).
In your shoes, I would do an investigative cut first - maybe where you
alread have loose blocks. Use a masonary drill on the top of the "concrete"
to drill down 1-2", then see how easy it is to chisel out a small section.
This will tell you how thick the screed is and also whether the DPM is just
Don't let me stop you, but I still think chasing the walls would be less
risky as you obviously have a quality floor - do you really want to disturb
Thanks for all your comments, most appreciated. I'm off out now to
saxophone quartet rehearsal so I will read it carefully tomorrow. Just
wanted to point out though that there is "screed", and when I said
"concrete floor" I was perhaps not being accurate enough. The question
as to its depth still remains, however.
Do remember that where new pipes feed a new rad old pipes do not need to be
removed from under the floor.
Can you run vertically in eg a cupboard then cut into the walls behind the
In the last year I have done more or less exactly the same - 1970's
bungalow, finger parquet block floor. We have just completed an extension as
well, including extending the heating and domestic hot/cold water..
Our existing floors are: uninsulated concrete slab, with painted on bitumen
DPC, then 25mm (ish) screed, and finally 10mm parquet blocks on more bitumen
with what looks like a felt layer embedded in between. The existing copper
pipes (heating and hot/cold services) were embedded directly into the 25mm
On arrival two years ago the heating system was badly sludged, and almost
cold in the bedrooms, so had to be chemically cleaned and flushed, which I
did over a spring month. This solved the sludge problem, but revealed that
the system had a number of tiny leaks, due presumably to corrosion and
differential restrained movement in the concrete. At the same time I changed
over to a wholly mains pressure heat bank hot and cold water system (due to
a poor head from our one storey cold tank), which then showed the same
pattern of small leaks in the pipework in the screed. I would suggest that
if your pipes are directly buried in the screed they are at the end of their
useful life, and you should probably consider another routing option. Trying
to find the leaks in the screed is likely to be difficult, frustrating,
ongoing, and to cause a lot of floor damage. Additionally, in a 60's house
you are likely to have an uninsulated floor slab, and a lot of heat will be
lost from pipes buried directly. This is wasteful (heating), and bloody
annoying in the winter - run the kitchen tap to hot, turn off, 2 mins later
it's cold again.
After considerable angst I bit the bullet and decided to renew the whole
heating and water system - now done. This has well insulated pipes in the
loft space in plastic, and drops in various places around the house in
copper and plastic as suits the application. I know vertical drops are
annoying, but they can mostly be hidden in cupboards etc - try to do drops
to a group of rads, with short horizontal runs above skirting and though
walls - if you are replacing rads (as we have), consider moving them to make
grouping near a drop easier. Additionally, if you are re-piping the whole
system you can split it into two or more zones, each with their own
As to the parquet - I've just laid a batch of reclaimed finger parquet in a
corridor to the new extension, and have re-laid some of our existing
parquet, which was loose. Both had bitumen adhesive on the back of the
blocks, which was difficult to remove, so I've re-laid them on bitumen
emulsion - ie paint on DPC liquid, which seems to work. Beware the fact that
the blocks all seem the same size, but are not! Make sure the floor is flat
if disturbed - use self levelling compound or similar. My laying method is
to dry lay the blocks, sorting them for best fit and packing well together.
Now tape over at right angles (I used parcel tape) to hold them together,
and cut into suitable sections (1 ft squares or as you like), and lift out
in sections. Now put a *good* layer of bitumen on the floor, restore the
taped sections, and overlay with thin battens weighted with heavy blocks or
similar. Leave 24 hours, remove the weights and tape, and clean up squooged
bitumen with white spirit - it comes off quite easily at this stage.
Best of luck with all this - it's a *lot* of work, but if done will leave
you with a much improved heating system, and beautiful floors.
Been there done that. 1970's house with bitumen stuck down parquet floor
with (leaking central heating) pipes embedded directly in the top layer
The pipes were leaking due to tiny corrosion pin holes, eventually working
its way between the parquet floor and causing an "always comes back" stain
on the carpet.
I removed the parquet over the pipe run using knife, chisel and bolster.
Came up quite easily where pipe was leaking. Pipe run easy to find easily
found as floor was hot when CH was on and wood was stained. Used petrol to
remove the bitumen glue, no problem. Had to angle grind out the pipe work as
hammer and chisel would have taken too long. I bolted a wooden batton to the
floor to act as an angle grinder guide, made a covering canopy of old sheets
between two ladders, climbed underneath with sutiable protective gear and
angle ground away. Hint, make sure you have enough spare angle grinder disks
(or buy a diamond blade) as had to make a B&Q trip half way through cutting.
Then used hammer and chisel (and more angle grinding) to remove the concrete
and pipe. Use a wet/dry vacumm to suck the pipe work dry before smashing to
pieces. My CH pipes went from back boiler across parquet floor lounge to
radiator and to radiator in hall way via a buried T.
I replaced with 15mm copper pipes sleeved in 22m Hep2O push fit plumbing
pipe. Had to have a solder joint in copper as run was a tad longer than 3m,
the Hep20 was continuous. The termations where it comes out the floor and T
piece were denzo taped as despite buying Hep2O rightangles + T peices you
can't actually get the copper pipe in and solder the copper joints (...think
about.....). I wanted to avoid the use of denzo tape but......The verticals
out of the floor were sleeved with 22m Hep2O again I tested thorughly before
covering the Hep2O with PVA and filled the groove with cement (+PVA...love
PVA....). smoothed flat. Left for ages to dry....
I stuck the parquet floor back (I got bitumen type glue from Homebase) but
some bits of wood were noticable bigger than others (due to damp ?), some
were almost black with mould and rest of floor was not too great anyway,
very large obvious gaps all over the place (I suspect fitted by previous
bodging owners) as well as not really being finished at some edges ie no
tiles fitted. I tried to get replacement wood pieces, but what I had was
clearly "imperial size" and all replacement would have been "metric" and a
lot of work sanding and shaping so in the end was carpeted over again. Also
carpet considerably warmer.
If I was doing it again I would buy a diamond blade disk, probably use a
bigger than 4" grinder and invest in an SDS hammer action chisel.
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