Advice needed

[Lemna gibba]

OK, this might sound like a silly question, but I hope you don't mind...

We are renovating our house. Originally, we planned to replace the entire ground floor with an insulated slab (150mm PIR) with 75mm screed and run UFH throughout the ground floor. Our plans have had to change such that we still plan to do our renovation, but will do it in two parts. We'll do the part marked kitchen and dining this year, and the rest of the house in 3-4 years. We can't do the whole floor now, as our plans involve removing internal walls and the cost just gets too much at the moment. We have a layout below with several loops, but will just do the green and blue loops this year. 

 

I can see a couple of possibilities. We could install these loops, and leave the screed in the corner (by the manifold and the door) free of pipes with the idea of digging the screed out in 3-4 years to run the other UFH loops through, when we do the rest of the house. But the more logical idea to me seems to be to install two manifolds in the kitchen now, and to put the other 4 manifolds on the same wall, but on the other side when we do the rest of the house in 3-4 years.  Is this possible? 

 

[Nickfromwales]

2 hours ago, Lemna gibba said:

But the more logical idea to me seems to be to install two manifolds in the kitchen now, and to put the other 4 manifolds on the same wall, but on the other side when we do the rest of the house in 3-4 years.  Is this possible? 

Ok. So you’ll only need one manifold here. Can you explain the above a bit better please? 😊

[Lemna gibba]

Let me try again. It didn't help that I said "manifold" when I meant port. 

 

In the long term we plan to run UFH throughout our house from an ASHP, with a unitower located where the manifold is in the schematic. Our house is currently unsuitable for a heat pump, but we are planning to get it heat-pump ready by concentrating on insulation and airtightness as we renovate our house. Due to costs, we will do our renovation in two phases. The first will be the rear extension (dining area) and kitchen.

 

We will replace the floor as port of this. Insulate with 150mm PIR and run UFH in this area. This should need a manifold with two ports, and by my understanding this can be run from our combi boiler with a two-port valve. In the coming years (3-4) we would then replace the floor in the rest of the house with an insulated slab and run the UFH throughout. We really can't afford this at the moment. At this stage we would need to replace our two-port manifold with a four port manifold, and the whole thing can be run from an ASHP. 

 

The problem that concerns me with the above plan, is that we would have to dig out a bit of the screed in front of the kitchen door in a few years, to add the additional UFH pipes for the rest of the house (as per the diagram). My concern is that as additional pipes came to the same manifold then we would need to dig out screed very close to the existing pipes. Perhaps this could be done carefully, and would be slightly easier if we used one of the egg crate mats that would help protect and locate the existing pipes. I'm not sure if I'm over worrying about this. 

 

My other thought was that when we do the rest of the house, is it feasible to have two manifolds (one 2-port serving the kitchen area & one 4-port serving the rest of the house). If we can do this, and locate them on different sides of the same wall, then we will not need to dig out the screed in the kitchen. I assume that this is possible, but have no idea if it is sensible?  I also might be overworrying about digging out the screed in the area by the kitchen door. 

[crispy_wafer]

So, install the 6 port manifold now, and cap the unused ports and do the rest of the UFH when the time comes.  Slide a bit of timber in to the screed to separate the installed pipes from the bit you will dig out later to protect them from kango damage.  - Is probably how I'd go about it...

[Jilly]

We have left 2 spare ports for an extension, we plan to come through the wall rather than go close to the existing pipes. I’m not certain exactly how it will work! it would be cheaper/less complicated than having another manifold, I would think, we need to ask the plumbers on here who seem to have missed your thread.  
How about asking Wunda for suggestions? They do a pipe map if you buy their kit (many folk on here have used them)

[Lemna gibba]

Thank you both. I think Crispy Wafer's suggestion sounds very good. I have a plan for the whole house UFH, but wanted to have an idea about what was possible. Jilly, we haven't spoke to underfloor. But had a very reasonable UK Underfloor Heating. Really appreciate your input.