Vinyl Flooring and Dampness

 Tel. 0191 4178192                                  E.mail:                               Mob. 07957 731995

                                     Vinyl flooring and dampness are words that can spell trouble.In particular sheet vinyl flooring and dampness just don't go together.Generally however in todays environment all houses must have damp proof membranes built into the concrete slab or subfloor when first built.So realistically dampness should not be a problem.Unfortunately when dampness does occur,in the form of rising damp through the floor,then usually the adhesive emulsifies and then debonds from the vinyl and the floor covering fails.With vinyl tiles there is obviously room for some moisture to evaporate,in between the joint with the next tile, up into the atmosphere.With welded sheet vinyl there is no where for the moisture to go.It becomes trapped and in time causes the floor to fail.To test for moisture a hygrometer is used.
Vinyl Flooring Hygrometer Test
In any new building with a newly poured concrete subfloor the concrete is classed as green.In general terms it takes approximately 1 month to dry out, or cure, for every 1 inch thickness of concrete.So for a standard 6 inch concrete slab it takes at least 6 months for it to be free of any moisture.Obviously this moisture in the mix cannot go downwards because according to building regulations there must be a damp proof membrane below.So it can only go upwards.On most building sites there is the added problems of the concrete floors being exposed to the elements and also Winter frosts and snow.All these things can effect quite dramatically how fast a new concrete slab dries out.With severe weather these floors just don't dry at all.
                            To test for moisture the digital hygrometer is used.This is the British Standard non invasive method of testing the % RH ( Relative Humidity ) or the moisture in the air coming through the concrete subfloor.The box shown above is stuck to the floor with butyl sealing tape and left overnight.The moisture evaporating from the concrete becomes trapped with the air in the box stuck to the floor and the hygrometer gives a % RH reading of how much water is in the air.Any reading of 75% RH or less and it's perfectly ok to proceed with laying sheet vinyl flooring.Any reading between 75% and 92% RH and the floor will need a damp proof membrane on the surface for the floor to  be laid at that time.Obviously 6 months later or however long it takes the concrete to dry,the damp proof membrane would not then be needed.For any reading higher than 92% RH  then it's not even advisable to proceed with the DPM.On building sites however time is paramount so rather than wait for the slab to dry out a damp proof membrane would be applied,assuming it was 92 % RH or below.
                             In old houses where perhaps there has never been a damp proof membrane fitted at all  or where there is general dampness apparent,where possibly a membrane has been damaged ,then it is sometimes advisable to use this simple test to avoid any problems.To see a DPM being laid just click on the link below.
       Tel 0191 4178192                            E.mail:                     Mob.07957 731995