Hi there
Just looking for some advice on septic tanks please…
We bought an old property last year with an additional cottage/barn close to it that we are hoping to convert at a later date (maybe 4-6 years time)
We have recently been looking into a new septic tank system to include pipe work to supply both buildings with a maximum number of 8 potential bedrooms (currently only has 3 in the main house but we are thinking long term with this place)
We have had a local guy look at the job and he has been in touch with SPANC
We haven’t had a total price yet but have had an indication that materials alone are going to be €10000!
I’ve looked online and am finding septic tanks in the region of €1-2000 with grease traps (which we’ve been told we need 2 of) in the region of €500-1000
I can’t comprehend that 100mm pipes and connections would run to €8000 and have no idea how much labour costs will be
Can anybody offer advice if they have had a similar system or anything like already installed and the costs involved?
Even better if it was in the Dordogne area and can give us a recommendation!
All the best
Sorry to let you know but our Septic Tank installed 4 years ago with a 4m3 tank cost approx €10k.
We had a 25m2 sand filter after the Septic Tank then connected to the local fosse.
Having had the work done I would install the next one myself as it looked fairly straight forward but if you want someone to do it it will cost a bit.
Just get a couple of quotes for different install options.
There are a lot of materials required, not just a few pipes!
There are at least 5 regards, all of which are special for the purpose and then numerous tonnes of special sand and aggregate. For 8 bedrooms the filter bed will be enormous together with the secondary bed beyond that.
I understand your surprise at the cost but you will have no change at 12k plus for a contractor to complete the work.
As a fully qualified and experienced builder of almost 50 years I installed my own a few years ago. Yes it saved me money but the work still has to be done and machinery hired etc. If you choose to do it yourself be prepared for SPANC to inspect your every move as when complete they have a responsibility to ensure that your installation is fit for the environment.
SPANC will tell you what type of installation you must have and where you can put it. Be respectful to them and they will look after you but if you treat if as a hole in the ground with a few pipes that anyone can do with their eyes closed then think again.
Property may still be cheaper here than in the UK but building materials and jobs to be done are not.
Speak to SPANC, get some plans drawn up for them to approve and then visit your local builders merchant who will happily provide you with a quote for all the materials required.
Then cost the plant and machinery you require and think where you are going to dispose of the excess excavation materials.
Then get 3 quotes from local contractors and compare them to your own costings.
Think hard about the price difference between DIY and a contractor and then if you still feel confident to do the work then go for it but just like dining at an all you can eat restaurant remember that your eyes are all too often bigger than your belly!!
Good luck with your project which ever you decide.
Where abouts in the Dordogne are you?
Sounds about right. We had a quote for a far smaller installation 4 years ago, at 8.5KE.
I installed a septic tank in Wales a while back. I don’t remember the exact cost, but it was nowhere near the prices quoted here.
I got the local JCB man to dig the trenches and lower the tank into a suitably sized hole. I laid the pipes myself and wheelbarrowed the gravel to cover the perforated pipes in the drainage field. Backfilling proved to be difficult because of the rocky nature of the ground, so I gave up on doing it myself with a shovel and call the JCB man back in. There was no equivalent of SPANC, just had the local planning inspector.
DIY can save a lot of money, but you can’t claim on anyone else if you get it wrong.
A professional installer has a lot of overheads. He needs to take into account the possibility that the job might take longer than expected. He has to pay wages and insurance, staff training, safety equipment and sick leave. Adverse weather or a viral pandemic could prevent him from working. Then TVA has to be paid on everything and finally he is entitled to make a profit on the job.
You also need to cost your own time. It will take an inexperienced person much longer than a professional team. Could you save more money by using the time to do something else?
Slightly diverging from this subject, our septic tank and drainage field have been under water for two months as a result of an exceptionally wet winter and we are not on a specially low lying site. Hopefully all will return to normal as the summer drought approaches and no damage will have been done. It took 130 thousand years for humans to get around to inventing the flushing toilet. Maybe we will need to quickly find a more efficient way of disposing of human waste as just one more solution to the problems of global warming.
Hi Ben and welcome to the forum.
As with most things… you should get at least 2 quotes for major works… such as this… from folk who are Registered and Insured to do the work.
Talking figures is a bit like discussing the length of a piece of string… 
… it is not until details are written down and can be checked, like for like… that you can get a proper idea of the costs involved.
Great advice John. I’m going to have to bite the bullet and replace my fosse later in the year. I knew that I’d have to d it eventually but at least I got nearly sixteen years out of the old one.
I have had my tank installed 10 years ago by Cantiran Assainissement. He did a grand job for a reasonable price, I had to have a Eparco system because I had no land for sand pit. Still very good inspected by saur las year, no problems, so far so good.