XPS board and flexy ady. Any tips for laying.

[ubdai]

Just about to lay down some XPS insulation boards for the UFH system and would like know the best way of getting the most contact between the board and the ady. ie do I do it the same way as with floortiles, place them into the ady and then give them little wriggle or is their a better method that can be used.
The xps boards seem to be semi flexible but can still snap if not careful when handling them

cheers
ubdai

 

[Andy Allen]

bed of adhesive, I normally use a 6mm trowel, put the boards down and wiggle them about, I normally stand on mine and do the shuffle...lol

 

[Rookery]

Are these the blue ones? What thickness are they?

 

[Lee@emctiles]

Are these the blue ones? What thickness are they?

What thickness are they once they have been trod all over and compressed???? Rendering them useless.....

Sorry.......hate these boards.......just my opinion and be debated many a time......there not fit for purpose.

 

[deanwessex]

Have to agree with Lee, you have to be very carefull not to crush them when laying

 

[Ajax123]

I too agree with lee...... Which is possibly a first??

great for screeding on top but tiling direct.... Not sure at all

 

[Diamond Pool Finishers]

And the screed needs to be 75mm thick as it is deemed a floating floor under BS , anything under is not -up to spec !!

 

[Ajax123]

And the screed needs to be 75mm thick as it is deemed a floating floor under BS , anything under is not -up to spec !!

65mm if domestic 75mm if its commercial and must be reinforced.

 

[DHTiling]

None cement faced extruded foam boards should be banned IMHO..

 

[Uheat - Keith]

Good morning all,

There is about six grades of the XPS boards, ours are the top grade, High Density and have a Compressive Strength of 300 kPa (BS EN 826) That is about a 30 stone man standing on them with no problem.
These boards have the same Thermal Conductivity as Construction boards as they both have the same core. Construction boards then have the 1mm fibreglass mesh embedded into a cement polymer mortar on each face.

Our Ekoboard sales are over 150000 sheets over 5+ years.
We installed these in our front office in 2006, the Tilers called off for three weeks and we walked over them for all that time, no problem.

We do advise that UFH and/or tiling should be carried out sooner, i.e next day after installing boards.
We also stock/sell Marmox.

Warm regards, Keith

 

[Lee@emctiles]

Here is a sample of an uncoated board, all i have done is press my big fat thumb on it.......it compresses....

 

[Lee@emctiles]

​was sent this by our supplier, makes interesting reading:

THE FACTS ON REINFORCED “PCS” CONSTRUCTION BOARDS VERSES PLAIN POLYSTYRENE BOARDS WHEN USED WITH ELECTRIC UNDERFLOOR HEATING.
For this purpose the cementitious reinforced thermal construction board shall be referred to as “PCS board” and the non-cement reinforced insulated board referred as “XPS” (extruded polystyrene)
Thermal value… Why is it important?
The thermal properties of the insulation board is the fundamental key in saving heat energy .If used with underfloor heating a significant increase in performance of heat-up times of tiles can be as great as 15 times faster than if no insulation is used.
The thermal value of both types of board PCS “cement reinforced” and XPS “non reinforced” get their insulation properties from the extruded foam.
The thermal value of the extruded foam can vary depending on the manufacturer and the type of blowing agents used. Some Manufacturers quote results based on DIN testing standards whilst others quote current BS EN standards. The different testing standards will give different results which are confusing when comparing results.
PCS boards have the thermal properties tested to BS EN 13164 2007 giving current and accurate data
XPS boards (dependant on manufacturer) prefer quoting DIN testing standards which often show more favourable results that may not be accurate if tested to BS EN standards

Point loading… Why is it important?
When laying insulation sheets on to any floor substrate, it goes without saying that the sheets will be walked upon by the fitter/installer during installation. It is the action of the installer kneeling and standing onto the sheet that produces a point load. This can crush or even snap the insulation if it is not reinforced. In situations where an electric under floor heating cable is installed point loading becomes a serious problem. If there is no reinforcement below the electrical heating cable, any force or weight applied can press the cable down and sink it into the insulation. If the insulation is crushed /compressed the thermal value of the insulation is reduced, also if the cable is forced into the insulation this will reduce the performance of the heating element due to the reduction of exposed surface area of the heating cable.
PCS boards have point loading capabilities and protect the insulation from damage during installation
XPS boards only have no resistance to point load and so becomes compressed and damaged during installation

Rigid construction… Why is it important?
For ease of application it is much easier to lay a lightweight rigid sheet over an uneven substrate as it will span slight unevenness easily. Problems arise when a using XPS boards less than 20mm thick as they are flexible and will follow any undulation in the floor substrate. As with all boards that are laid onto floors, an amount of force needs to be applied to the sheet to firmly fix it down into the adhesive. With cement reinforced boards this works fine as the force is distributed evenly, but when force is applied to a XPS board, the area where the force is applied is the only area that gets forced into the adhesive resulting in an undulating surface.
PCS boards are lightweight yet very rigid providing easy installation
XPS boards are extremely flexible making installation difficult

Impact resistance …Why is it important?
With every installation, the sheets will have to be Moved/Carried and possibly cut to fit. This movement of the boards especially in confined spaces where there are fixed objects i.e. Bathtubs/Kitchen units, walls etc can cause the boards to become damaged through impact against hard surfaces..PCS board can withstand these knocks during installation compared to a plain XPS foam sheet that are prone to substantial damage and snap easily.
PCS boards resist impact and will not be affected as a result of accidental knocks during installation.
XPS boards have no resistance to impact and break very easily as a result of accidental knocks during installation.

 

[Gazzer]

I had to use some of these XPS boards from UHeat about 2 years ago, Ok the floor is no problem but even my size 13s that should act like snow shoes were leaving imprints and kneeling on them was worse...never again.

 

[Ajax123]

I guess the average tiler drops to his knees rather than carefully places his knees against the floor. So what is the loading of this action.

we have to make a number of assumptions of course so lets say a tiler weighing 100kg drops to us knees under a cantilevered load (his ankles acting as the cantilever) from a height of approximately 0.25m the length f he average ankle to knee measurement.

This would offer a kinetic energy of some 245Joules and an impact force of some 2450Newtons. The average knee I guess is maybe 10cm by 10cm giving an area of 0.01m2 or 1hundredth of a square meter. Are you with me so far ??

Calculating the equivalent force per square meter you get appoint load of some 245000N/m2 or 245 kN/m2....

Normal XPS is rated at 250kpa so a pressure of 250kpa will compress the board by 10% of its depth. 1kpa is equivalent to 1kN/m2

its no wonder you dent the xps when you kneel on it.... Fatty