Pumped drainage system?

[Fridayschild]

I'd like to do some interior work to my loft conversion to turn one big bedroom and a big bathroom into two single bedrooms and a shower room. This means moving the Loo and shower. Without a lot of preliminary floorboard lifting my builder doesn't want to predict whether there will be enough fall for the drains to actually drain down to the outside wall. He says if I can take the risk there won't be enough space I could have a pumped drainage system as my plan B. Architect suggests I just get on and have floorboards lifted, which is not really all that helpful.

Has anyone got any experience of pumped drainage systems or views on them?

avoid them saniflo system is what they are on about might b ok for shower and sink but toilet are notorious for blocking .They are basically a liquidister on the back of the pan too much paper or wet wipe tampons or anything like that it will break the first thing you will notice it backing and chances are when its being fixed the contents will end up EVERYWHERE and also they are noisy .Just look on hear search for threads about saniflo

Well... you shouldn’t be putting tampons and wet wipes into any toilets in the forst place, walker so that of course would break any systems. I can’t believe peope these days are still doing that.
We’ll have one of these pumps in the kitchen only so no experience yet.

My whole house is on a pumped system. It's fine most of the time but if there is a power cut there is no way to pump.

We have a backup generator & pump for emergencies when we lose power for a prolonged period.

Also, it will incorporate a macerator. You have to be very vigilant about what goes down the loo & sink. If it isn't loo paper, wee or poo, it doesn't go down.

No hair, no tampons, no wipes, no moist loo paper, no fat, not waste food etc.

And you have to make sure everyone in the house & your guests follow the rules.

We have ours serviced every year or two

We did the same in our chalet bungalow. We have eaves storage so the drainage from the toilet (which was previously on the other side of the house) goes back into the eaves and across to the outside wall, the 4ft eaves space gives plenty room for an adequate fall.
We had to do the whole floorboard lift too as the architect suspected we might need to double joist where the new partition walls were, it's not as bad as it sounds.

Avoid saniflo if you do go for it, as they’re bloody expensive, and utterly useless. Uniflo are great, half the price, last twice as long, and have good technical support to help with problems, and sell spare parts (you can replace the entire inside easily so less aggro), and macerator friendly cleaning crystals etc. You can’t use bleach with macerators because it destroys the rubber seals, so must use gentler cleaners. You do adapt quite quickly to having one, including the noise!

I'd want to know how it would work before starting so would check the depth. I don't understand why your builder seems to think it's so hard to do.

Thank you all - very helpful.

Moving the flooring just to look also involves emptying and moving a wardrobe and moving a very heavy bed. I am with the builder on this one tbh!