Lifting floorboars - any advice?

[robinkeith]

Hello everyone,
I'm new to the forum, and new to old houses, so please excuse what I'm sure will be dumb questions.
We're renovating our 'new' house c1850, and want to put in underfloor heating, so we can go solar at some point in the future. To lay the pipe, I need to get up the floorboards, which I guess are original. Some of them are a foot or so wide. and it would be a shame to destroy them in the process.

Just wondered if any has ideas for lifting floorboards without doing too much damage?

Thanks very much

 

[Nigel Watts]

If a significant area of the floor has to be lifted it will be almost impossible to avoid damaging and cutting the boards. In Victorian houses the boards not only go under the skirting boards but often also go under internal studwork walls. Such boards can only be lifted if they are cut.

SPAB used to (and may still) do a good leaflet on how to look after and repair floorboards which I think includes advice on how to lift them. The initial prising up of a section of board needs to be done with care so as not to damage the adjacent board. Wooden wedges should then be inserted as the next section is lifted. Old fashioned cut nails used to fix the boards have the advantage of being wedge shaped, so once you have lifted them a little distance they will be free.

Personally if I had a fine floor with good wide boards I would go to great lengths to avoid having to lift it.

 

[JoceAndChris]

Great post from Nigel, agree with all of that. My father in law has been banned from working on this house since ruining some of our floorboards - it's so easy to damage them.

I don't think under floor heating and solar power is right for an 1850s house personally and I certainly wouldn't buy a period property characterised by those things.

Each to their own, but please be very slow and careful if they're nice old boards.

 

[Andrew Bodenham]

Hello, robinkeith,

Welcome to the forum; you'll find lots of good advice here, and lots of opinions. Bear in mind that you may not always get what you want to hear, but I suppose that's how we learn stuff and reflect on our plans and ideas.

Now, about these floorboards...

For a start I don't see the link between solar power and UFH. All the solar systems I've seen are used for water heating rather than space heating. Solar 'availability' is diametrically opposed to heating demand, i.e. you want heat on a cold winter evening, not at noon in midsummer, so you'll need another heat source in the system. I'd be surprised if solar space heating was economically viable in terms of the capital cost against energy produced, but others may be able relate their experiences of this.

If you did decide to go for UFH then be prepared to destroy your existing floor. Old floorboards are extremely hard to lift without damage, wide ones even moreso. The nails are often rusted into the joists, so that ripping them through the back of the boards by force is the only option. Doing this often splits the boards, or causes sections to break off near the end of boards. Generally a bit of disaster. If your floor has any sort of aesthetic or historical value I would not recommend this course of action.

Even if you do manage to lift the floor and install UFH you can then look forward to the problems caused by shrinkage as the woodwork adapts to the new heating condition. You'll also have to work in adequate insulation, and find somewhere for the control gear (manifold, mixing valves etc) to go. At a later date you may have to cope with the consequences of rodent damage to the pipework and subsequent leaks.

You'll gather that I'm not a huge fan of UFH, especially as a retro-fit system in older properties. You can't go wrong with some radiators piped up with good old fashioned copper.

Can you sense a general opinion developing among your respondents......

 

[Flyfisher]

I've no direct experience of underfloor heating systems but everything I've read has described installations in a solid floor such that the floor becomes a sort of gentle storage heater. For maximum effectiveness, good insulation is required below the new slab containing the pipework otherwise a lot of heat will be lost to the underlying ground instead of entering the house. Other threads here have described such works and the depths of excavation that may be required for a truly effective underfloor system (up to 15 inches I seem to recall).

I may have misinterpreted the intention here, but simply laying pipes below an existing wooden floor does not seem likely to result in an efficient heating system - and efficiency is key to such systems considering the relatively low level of heat energy that can be collected by solar systems.

All of that is quite apart from the understandable concerns about damaging or destroying historic flooring; such a thing would be unfortunate in itself but might be considered unforgiveable if the end result is ineffective anyway.

 

[skier-hughes]

Is the house listed?
Has the CO given permission for such works?

Underfloor heating works best in well insulated houses, so as well as the floor insulation, you'll need to think about insulating your walls, windows etc to get the full benefit of a very low heat source.

We have 50 solar tubes, (as well as a wood burner with back boiler and a rayburn) heating a 900 litre buffer tank, which heats a 200l DHW tank and supplies our heating via radiators.

On a very bright sunny winters day the solar will supply a small amount of water heating, but if the day has got off very cold and we have lit the fire, then most of the heating comes from the fire and any heat generated by the sun is often too small to make a difference or even to start the pump as the fire has already heated the water too much.

Of course today it is pumping heat into the tank at a fair rate of knots, we are getting tank temps of 65', and as the night temps drop quite drastically, and we had friends over who don't wear thick jumpers it has provided plenty of heating.

From my experience, I would not look at solar panels for central heating, apart from a secondary source.

Fly, when you coming up to look at the system? We have a party Saturday if you want something to eat while you are here, Abi's busy cooking as I type

 

[Flyfisher]

Now there's a very timely prod. You have PM.

 

[MatthewC]

I strongly agree with the posts from Andrew and Nigel. I wish my house (of the same vintage) had such lovely wide floorboards - I would think twice and again before lifting them.

The SPAB leaflet on floors is still available as I was given a copy at Christmas - see the publications on their website.

Matthew
http://houseintheenchantedforest.blogspot.com/

 

[AMc]

Hello everyone,
I'm new to the forum, and new to old houses, so please excuse what I'm sure will be dumb questions.
We're renovating our 'new' house c1850, and want to put in underfloor heating, so we can go solar at some point in the future. To lay the pipe, I need to get up the floorboards, which I guess are original. Some of them are a foot or so wide. and it would be a shame to destroy them in the process.

Just wondered if any has ideas for lifting floorboards without doing too much damage?

Thanks very much

If you're thinking about lifting the floorboards then you're a few steps ahead of yourself.

I have an old house and have lifted the floorboards and fitted underfloor heating fed by a heat pump. It needs very careful planning, very high quality workmanship installing the insulation and it needs IMHO professional expert design - not the back of the envelope calculations you can use for a typlical boiler and rads installation.

I second the comments about solar heating - it's not going to work and if its been suggested to you by a supplier walk away as there are a lot of underskilled people in that area.
There simply isn't enough solar energy available in the short winter day to warm the inside of a well insulated modern house through the night - if it were possible then new houses wouldn't have boilers. Older houses are much less thermally efficient because of their construction and some things can't be retro fitted.

Single glazing, solid walls are simply too thermally inefficient to heat with low temperature underfloor heating unless you are able to insulate the walls, floors and ceiling to modern levels and secondary/double glaze.

Ground source heat pumps use the solar energy stored below the surface of the ground during summer to feed low temperature underfloor heating through the winter- which may be what you're suggesting?

You are restricted to the flow temperatures you can use in underfloor heating at all and under old wood especially. Wood is also a great insulator and most UFH is designed to work with solid ceramic floor coverings which work like a storage heater and also provide good heat transfer characteristics.
If you need more heat with a radiator system you can pump the flow temp. up to 65C - if you do that with a wood floor you'll split and warp the boards and hurt your feet walking around!

I have experienced a winter with underfloor heating that wasn't adequately installed and a heat pump that wasn't up to the heat load needed. I wouldn't recommend it. I would take a breath (as you have a summer) and get more information before you start thinking about lifting the floors. It can be done and it is lovely if it's installed right but it is full of pitfalls and lifting the floorboards is one of the more minor obstacles to overcome (albeit important to get right).