Sunday 22 December 2013

Case-study: Duoplank on Underfloor Heating

"As self-builders, we are very involved in specifying the materials used in our house.  We wanted the look and feel of real oak planks but without too many of the difficulties associated with the shrinkage of natural oak.  We quickly identified the Duoplank product through its UK distributor Wood-You-Like in Kent. This is an Engineered Board made with a wide top solid layer of natural oak and a high-quality birch ply substrate, critical to us because we were installing on concrete with UFH embedded in the floor.
We visited the showroom near Ashford and received plenty of good advice from theRural Berskhirecompany and felt we were dealing with people who actually installed the product, as well as supply them. 
From the wide range of oak qualities available we selected the 'Rustic' range as being closest to the effect we sought to create in our new-build, which is a Georgian-style farmhouse of brick and tile exterior.
Installing the product was easier than we expected, the longest task being the selecting and cutting of the planks.  As we tackled each room, we initially placed them in position 'dry' on the floor to check for colour-match and fit.  The planks slot together using a tongue-and-groove formation.  The Duoplank manufacturer had taken care to chamfer the bottom edges of the planking, avoiding any chance of surplus glue seeping into the tongue-and-grooves.  We used a chop-saw to cut each edging plank to length.  This made light work of the cutting task; the engineered product seems as dense as working with solid oak. We glued the rows of board to the floor, three or four at a time.  Duoplank Oak Rustic glued to UnderfloorheatingWood-You-Like had given us a clear fact-sheet on how to pre-condition the boards and the temperature of the floor during the installation.  This ensures that the boards have a normal amount of humidity on installation.  Unlike a conventionally heated house, using UFH wood flooring shrinks slightly in the winter whilst heat is drawn up through the floor.
Wood-You-Like advised us on the size of the gap to leave around the wall edges - 15mm in our case  - and we used chipboard spacers to maintain this gap and hold the edges firm whilst we glued and fitted each successive row.
We found a notched trowel to be the best tool for Notched trowelspreading the glue evenly.  It was important for us to eliminate air gaps under the boards to maximise heat transfer from the screed into the wood.  We managed this by spreading the glue 'notches' at 90 degrees to the board lengths, which enables one to see better where the boards are not fully seated, as glue oozes out slightly at the working edge.  We used bricks as a temporary method of holding down any 'high' areas of board during setting; this task certainly showed up minor inadequacies in the flatness of the screed subfloor!  Fitting the 25mm wide skirting board around the rooms to cover this gap has completed the finished appearance.
The glue sets in 24 hours and we followed the detailed instructions for gradually applyingWood You Like, Duoplank Oak Rustic brushed and oiled natural heat into the flooring to slowly dry out the wood.  During our first winter heating season this has opened up a 1mm gap at many of the board long edges - or about 0.05% total shrinkage compared to the summer state, when we expect the gap to close up again.  We are more than happy with this result over UFH, and our choice of Engineering Board to provide the visual effect that we sought."
John and Julie - West Berkshire