Plumbing issues in a house modernisation

Three questions, but I have included them in the one post because they are related.

I purchased a house in Code Postale 33580 back in October 2016. A French architect was engaged prior to purchase, but work has yet to commence.The two plumbers invited by the archiect (who will project manage the work co-ordinating the various trades)to submit devis not only want to choose the showers, sinks, basins, water heaters etc. but are selecting the most expensive brands and charging (fitting the components is a separate element in the devis) more(without VAT @10% ) than plumber’s merchants price inclusive of VAT @ 20%… I welcome other subscribers comments.

On a technical issue do any subscribers have any experience using a macerator unit in an ensuite (WC, basin, sink) to a fosse septique?

The fosse is “non-conforme”, I prefer a “micro-station” because my research suggests that a filtyer bed is not a cost effective solution. I expect to visit the house for a few days every month of the year and most of June to August. Do any subscribers have any experience using solar power to supply the “micro-station” or is a once a month flush sufficient to keep the system working?

Hi John…

Friends had a house rebuilt after fire destroyed it… so that is where my “advice” comes from…

The Architect is working for the Owner… if the Devis are NOT for what the Owners want… get other Devis… perhaps an indepth-discussion between the Architect and the Owner is needed (as to budget etc for each section). Final approval from the Owners needed… before purchasing and fitting in Bathroom/Kitchen etc etc…

Just a thought… does the Architect have any “link” with these Plumbers…??? might be an idea to try to widen the net…:wink:


When we did a full house renovation 5 years ago, the small company we used to all of the work (elec, plumbing, interior walls, full decorating etc) agreed that I bought all of the items we wanted to install and then they installed them.

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Macerator to fosse septique: I am presuming you are having this to use smaller sewage pipework ???

The only problem I have heard of is one occasion when a visitor used way too much toilet paper and blocked the macerator…:scream: The householder was not pleased… he had to get hands-on with that …yuk…:stuck_out_tongue_closed_eyes:

I am sure folks, who actually have one themselves, will chime in…

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I think you met find that you shouldn’t use a microstation on a holiday home as they need a permanent power supply.

Yes, but not all of them require power. @Andrew_Barnes can advise on this perhaps?

[quote=“John_Wellum, post:1, topic:15622”]
On a technical issue do any subscribers have any experience using a macerator unit in an ensuite (WC, basin, sink) to a fosse septique?
[/quote]Yes, we use one for a groundfloor WC that was too far from the FTE (fosse toutes eaux) to get enough fall, plus there was no room for 100mm pipework. You need to ensure that your system is ventilated correctly (open vents as opposed to one way “durgo” type valves) as the macerator can blow air out through waste traps due to the pressure involved. This is at best annoying (noises) & at worst a bit smelly. You can fit one way valves in waste pipes to limit the scope of such blow back.

Just say, “no”. it’s your home and it’s for you to choose the fitments, it’s you who will be using them. If they don’t like it, I promise you that there are many other plumbers out there who would be grateful for the work. Macerator units can be useful, if they are a technical necessity, otherwise why? If they break down, it’s a nightmare; have you ever cleaned out a macerator lavatory - I have, never again. If you want a micro-station, you should have a micro-station. You are paying and in the end, you need to make sure that you get what you want. At the moment and based upon what you have written, you may be being taken advantage of, but that’s for you to know and me to guess at.

You must be quite near us (33580 St Ferme).

Why not consider doing the plumbing yourself. Its not really very difficult and although you may be slower than a plumber you will save a lot and will get it done the way you want not the way he wants!

I have done all my plumbing including the drains. The pipework is much easier than the drains. I would use UK pipe and fittings (much cheaper than French). The sizes are different but all end fittings (taps, ballcocks etc) are 1/2 BSP in both France and UK so no probs with these. French plumbers tend to undersize the pipework so you may have problems if you have several showers etc. I would always use 22mm main feeds (the plumber will probably suggest 16mm and will say this is OK as pressure is much higher in France. True about pressure but flow will still be restricted and if you run two or more showers off the same feed you will be unhappy. I used 22mm and 15mm plastic pipes and fittings. You will find that French plumbing fittings can cost over x2 UK prices. For CH pipes you need to use the special barrier pipe. Use French drains as they use 100mm for main soil (UK is 110mm) and other drain sizes don’t match UK but for manholes I would get these in UK as they are properly “benched” and the French “roundabout” tyope are hopeless and block easily. You can fit a French 100mm pipe into the UK manhole either by using the expanded end in the fitting or by using a 100mm straight coupling which will fit nicely into the 110mm ring seal opening in the manhole. I use vented traps form UK for all our basins (you can’t get these in France). You can adapt a French 40mm drain pipe to fit over a short length of UK drain by warming it up and easing it open over the handle of an old wooden handled screwdriver (or make a special “dilator” to suit. Its quite easy and works well. UK traps fit French plugholes spigots as they are still in BSP sizes.

Jonathan (Badger) may not agree but I have done all the wiring as well. Not too hard if you use Comme un Pro as long as it’s not 3 phase. **If you have 3 phase DON’T TRY TO DO IT YOURSELF - it can kill you.

We are back in France at the end of May until August so if you would like some local advice |I would be happy to help. I won’t have time to do any work for you!

I would avoid a macerator if at all possible… Whatever people say they are noisy.

PM me if you want more.

[quote=“Michael_Blackmore, post:9, topic:15622”]…as long as it’s not 3 phase. **If you have 3 phase DON’T TRY TO DO IT YOURSELF - it can kill you.[/quote]…& so can single phase, it just might not do it as quickly.

The main point is that if you have any doubts about what you are doing with electricity (or plumbing, come to that) then get someone with proper knowledge to help.

Personally I wouldn’t advocate using UK pipework as you don’t want to find that a simple fix with an item off the shelf here in France isn’t possible witohut recourse to an international courrier.


Hi Jonathan

Good to hear from you again… Of course you are right about the risk but I
hope you approve of the severe warning about 3 phase. Plumbing is much

I agree about repairs but I keep a small stock of fittings etc to deal with

Hope your latest project is going well.



I have completely rewired my home, and had no probs with an edf inspection. I thought about buying UK electrics but was warned by my insurance co. that it could annule my cover, the architect is employed by you, the plumbers by you, go out and buy your choice of bath etc. Plumbers install their work is at a lower rate it tva not the baths etc

You were quite right not to use UK electrics as they would not have complied and if the EDF inspector had looked at all he would have failed it. UK cable does not have a separately insulated earth wire and the earth is smaller than the power conductors. French are all the same and each wire is individually insulated. All French circuit breakers are double pole, UK are single so they would have failed as well. You just have to bite the bullet over the costs!

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We are at Neuffons so quite close.
Useful information - as are all the posts, many thanks to all, those who have and those about to reply.
We explained to the architect when we first met that one reason for engaging them was to get french prices rather than “prix etrangers”. I can do most of the electrics and most of the plumbing - there are some very useful YouTube videos in french on both. Michael’s guidance re french rather than english sourcing are invaluable. I also have the opportunity of sourcing in Spain
Macerators are a consideration a) a WC on the first floor north side and the fosse is on the south side, b) the two new proposed en-suite outlets into the current fosse are too low and would require a new fosse at a deeper level now, rather than at the end of the project.
I can see that the water is hard. Is the extra cost of a steatite water heater justified? Guaranteed life span seems similar.
We expect to be at Neuffons for several weeks from June, perhaps we can meet up

Hi John…

Have SPANC (Le Service Public d’Assainissement Non Collectif) in your region, been in touch re the current Fosse and your proposed alterations ??

No! and perversely we have yet to have a copy of their non-conforme report. That is not quite as bad as it reads. The Notaire on completion had a copy and the issue is lack of filtration. The Notaire “published” some time ago and we are due a small refund (200 euros) but we had to go into their office early April to enquire re progress that a) we were due a refund and b) we would get all papers including SPANC after they had made the refund. The architect has spoken to SPANC and they require the standard soil survey.
We do intend to bring it upto standard (it makes resell in 10+ years time easier ) but as all things it is a matter of budget control and getting the best value for money. My research points to filtration beds having a limited life before they need renewing. Most micro-station require an electricity supply, but as James as pointed out not all, I also understand that a once a month “flush” will keep the system operating, and will consider solar panels to supply the micro-station with electricity.
As other subscribers may have found for a country that is so technically advanced in some areas there can be a bureaucratic hesitation to consider other alternatives to “it worked for grandad”

Hi John…

I only asked as our Mairie have not been able to agree a recent Planning Application (for extending habitable surface area) until a dossier is opened by SPANC. The Dossier Number needs to be entered onto the Planning Application, it seems…

The new Owners knew the Fosse “did not conform” (like you, no Report as such)… and they were intending to get it sorted at some time anyway… but now we have to get SPANC in asap in order that the renovation work does not get delayed.

I’ve arranged a Site Visit with SPANC and the new Owners, next week, and then (hopefully) everything can forge ahead. :slight_smile:

Good advice on the whole but by using british pipework you won’t be able to get it passed if you wish to sell the property. It may not be a problem but can be. Using British manholes in French Drainage systems is not allowed however rubbish the plastic French ones are. As we know all systems are being checked now and must confirm especially if you wish to resell. This can depend on department though. I once bought in B&Q in the UK a compression fitting which had 15mm at one end and 16mm at the other!!! They were sold as 15mm straight couplers lolol. I bought the lot so if there’s a local problem and you needed to use French sizes - problem solved. I have never checked yo see if you could buy them online for example. 8 only use 16mm piping have three showers and never have a drop in pressure if they are used together. 22mm isn’t necessary due to the recommended 4bar pressure in the house. Good luck.

An interesting point but since plumbing was not part of the inspection
report when we bought the house in 2010 I don’t think this would be a
problem. Given the very cursory inspection for the very detailed report
anyway I cannot imagine they would measure any of the pipework, most of
which is not visible anyway.

In spite of being “passed” our electrical system was lethal with no
functioning earth and many of the inadequate circuit breakers having the
polarity the wrong way round. Several sockets were not earthed and the
links between the two tableaux were so far below the norms as to be a fire
risk. So much for “experts”.

The 15/16 adaptors are interesting but, I suspect hard to find. If you
used all French sizes why did you need them?

I am pleased your showers are OK on 16mm feeds (I assume you mean there is
a main 16 from the tank to the branches to the showers). I know of others
who are not so lucky. The 4 Bar is nominal and may not be maintained all
the time depending on other demands up stream (eg farms washing down yards
or intermittent heavy users such as wineries.)

1/2" BSP is the same in both countries, you can use UK bought fittings with 14mm French pipe (and 16mm, I think) if you use French olives and nuts - so any straight 1/2" BSP compression coupling can be used to go from UK 15mm to 14 or 16mm.

That said I can’t see why you would bother with 15mm pipe in France because the French don’t sell anything else which will work with it - all the capillary fittings are either 14mm or 16mm. About the only reason I can think of is that 15mm UK copper tube is almost certainly cheaper than 16mm French tube and probably cheaper than 14mm but that is at because there is less copper in it as French copper tube has a 1mm wall thickness and UK copper tube has an 0.7mm wall thickness.

For the sinks in the kitchen&utility I used 12mm pipe (sourced in the UK as it happens so “thin” walls) - mainly because the flexible tails on the taps terminated in 12mm fittings anyway so I had to go down to 12mm at some point and I had to get two pipes through an existing, narrow channel.