Solid wood floors over wet UFH - bad idea?

[Omgiamgoingtobuildahouse]

Hi everyone. Long story short, we know we should use engineered wood over our wet UFH but we want to use solid wood. I know we are not supposed to as solid wood will expand/contract and we may get humps appearing and potentially cracking of walls. I know this is true as have had it in another house - huge humps appearing overnight. However, the old house was block and brick and draughty and the underfloor heating was driven by a gas boiler at a much higher temp. The flooring was also quite new. We are now nearing the finish of our MBC new build with airtightness at 0.73 and a GSHP, providing UFH that will probably hardy ever be on and when it is at a much lower temp, am I safe to go with solid wood? Anyone help from anyone that has done this or any reasons why we shouldn't would be gratefully received. Many thanks!

[PeterW]

35c max flow and bond the wood to the concrete with something like Sika 5500s, and also for safety get a floor product that has grooves cut in the back to stop any cupping. Will be fine with that lot. 

[ProDave]

Ask the floor supplier for something they guarantee will be okay with UFH.  That will almost certainly mean not solid oak, and whatever you choose will be narrow planks.  Our last house had 90mm solid Maple and that was okay.

 

(Present house has 190mm wide engineered oak and is fine)

 

What have you got against Engineered boards?

[Omgiamgoingtobuildahouse]

Nothing against engineered but looking at possible ways to bring the cost down and we have a 25mm gap to fill. Many thanks for your reply!

[Temp]

I would question why you want to use solid wood? If you use decent quality engineered Wood you cannot tell the difference once its down. It can also be resanded as many times as solid before the T&G fails. You can also have wider boards without risk of cupping and I think wider boards look better. Ours is about 200mm wide.

 

The only advantage of solid is that its slightly cheaper than the best engineered wood!

 

Edited October 6, 2020 by Temp

[patp]

Can't help but just wanted to say that I love your username!

[Omgiamgoingtobuildahouse]

Any pointers on where to buy engineered? Internet is a mine field!

[ProDave]

I went to the local flooring material shop in town.  They took my requirements, sent of for some samples so I could see them in the flesh, then ordered what I needed.

 

I am not sure flooring is something I would want to buy on line without seeing it for real.

[Temp]

Got ours from Woods of Wales. 21mm Oak pretreated with hardwax oil.

[Omgiamgoingtobuildahouse]

4 hours ago, Temp said:

I would question why you want to use solid wood? If you use decent quality engineered Wood you cannot tell the difference once its down. It can also be resanded as many times as solid before the T&G fails. You can also have wider boards without risk of cupping and I think wider boards look better. Ours is about 200mm wide.

 

The only advantage of solid is that its slightly cheaper than the best engineered wood!

 

its complicated but i need a thicker piece of wood to maintain a level threshold. most engineered is fairly thin, 14mm or so  and 20 mm thickness is more expensive. We are running out of money and are looking to keep the cost down. I can et to 25mm and save money by buying a solid wood floor so its all down to cost really. Nothing against engineered. The look is the same.  I am just worried about humps if I use solid wood as i experienced previously albeit in a different kind of house

.

Edited October 6, 2020 by Omgiamgoingtobuildahouse

[Omgiamgoingtobuildahouse]

4 hours ago, patp said:

Can't help but just wanted to say that I love your username!

Thanks. Can't actually believe we have done it. It's like a dream. I am going to wake up like Bobby in Dallas!

[Omgiamgoingtobuildahouse]

5 hours ago, ProDave said:

Ask the floor supplier for something they guarantee will be okay with UFH.  That will almost certainly mean not solid oak, and whatever you choose will be narrow planks.  Our last house had 90mm solid Maple and that was okay.

 

(Present house has 190mm wide engineered oak and is fine)

 

What have you got against Engineered boards?

Hi Dave. Nothing against and I want wide boards. See other replies for reasons. 

[ProDave]

Engineered boards are available in different thicknesses.  Use a thick one and it's a structural board, capable of spanning between joists so no need for a sub floor.

[recoveringbuilder]

I have used engineered wood in our last three houses, originally wanted solid American black walnut but the company I was dealing with said no good with the ufh. One company I have dealt with online was ukflooringdirect, we had all our engineered stuff from them and they are great at sending out samples, we’ve had engineered oak in different widths and all good quality, we have only used laminate this time but bought it all from them too.