I went back to a job last week to fit a carpet and noticed the knight tile I had laid 2 years ago has gapped on the sides and the edges quite badly. It is in a conservatory on plywood stuck down with ht. Ply was laid out and screwed down for a few weeks prior to me coming in stapling and feathering it. I dont like Karndean as it is and looking at this floor I dont fancy laying it again. Problem is I cant remember if it was installed on fball ht or Karndeans ht. Ive never had this problem with any of Amticos products, even if some spacia is cut poorly, id still rather fit that
I always use karndeans own glue, same as amtico, i use their own as well. On polyflor and other lvts i use f balls own. Its more to cover my own arse in case of anything down the road.
Gapping in LVT's is normally caused by the LVT being to warm when fitted of the subfloor moving. HT adhesive will not help this.
I've been discussing this a lot recently with Matt and Paul Howells (the chief instructor from Amtico). Paul generally said most underestimate the heat in a conservatory floor and the tiles expand during installation even if they are kept cool prior to laying. Of course when the conservatory cools at night the tiles contract as the HT adhesive needs 24 hours to set. The general consensus is for a conservatory every measure needs to be taken to maintain a steady temperature for at least a 24 hour period. Direct sunlight needs to be blocked off with sheets and possibly a portable aircon unit being used (that's one of Matt's). Following that heating may need to be used to stop the conservatory cooling too much overnight. I also have a theory gaps appear quite early but aren't noticed until they fill with dirt. I know it seems a lot of hassle to take all these measures but conservatories are relatively quick to lay so well worth taking some precautions. A lot of companies I know won't do conservatories for the reason of gapping in the tiles.
Done a conservatory about januray last year in Karndean wood planks di Vinci. It was freezing cold and there is no rad in there so I used a calor gas heater to keep heat in room but waste of time as the heat just when straight out the roof.So properly laid in cold temperature. Laid planks in HT, was there in march and floor looks great, no gaps. The sun only comes in late afternoon the lady said an hardly touches the floor. So would it be better to lay in cold? It it ok because there is no sun direct to floor? My main work is LVTs so need to get every job spot on.
Yes, always lay LVT colder than what the room will be. Conservatories should have the windows covered up if its sunny while laying. Ideally you should take the subfloor temperature etc and compare it to say the subfloor of maybe the kitchen in the same property. The LVT will grow with heat so you want it cold while fitting. if its the other way around the LVT will shrink after fitting which will leave gaps
Surely you don't want it too much cooler Matt. I mean you don't want woodplank tiles to tent at the ends.
No you don't want it to much cooler! As it can tent like you say. But you would have to fit it loads colder for that to happen. Tenting on ends is normally caused by the subfloor moving tho. However, if you fit the LVT using F46 then if ever it did tent (tenting through heat change will normally pop up one board on that row) you can simply pull that plank out and stick it in the guillotine and drop back in. I would much prefer to trim one or two boards rather than have to replace the whole floor because of gapping Someone asked for a guide. The guide is, (simple guide) fit the product colder than what the rooms average temperature will be by a couple of degrees. If the rooms average temp is 19c, and the LVT to be fitted is 24c (as been in back of van or stored in a warm place maybe) then obviously the LVT will shrink when fitted. In conservatories you also need to take the subfloor temp! The subfloor may be 25c as the screed is absorbing the heat from the sun, but the air temp may only be 18c. You may have your product at 18c also, but you fit on the hot base, as you fit the lvt it will be starting to absorb the subfloor heat and growing. When the place cools down again the LVT will shrink also. Treat a conservatory as if it has underfloor heating. YOU NEED THIS TURNED OFF ! You have to amke sure you can keep the floor cool. This is also why i recommend F46 over HT adhesive. F46 is the recommended adhesive over underfloor heating. Not HT! Work that one out LOL.
No,i said that if an experienced installer has laid it to shall we say "over-fit" then i dont understand it!,that being i havent seen this before,it can happen because the subfloor being a differing mover than the top laid product.Inexperience especially in a conservatory could bring to light this action as an example.
Its annoying because it doesnt always happen. Otherwise every lvt Ive laid on a hot day on to a cold screed you would expect to shrink. Is the material its made of changing from time to time? I appreciate all the advise tho, last week I did a bathroom and I used f46 and rollerd it like ive seen done on this forum. I couldnt believe how well it stuck. That conservatory was fitted on a hot day so it makes sense whats being said. I wasnt told about that at Amtico.
I used a little gloss roller as it was a small area, Ive heard of people rolling the glue to stop the adhesive shadowing through but Ive never seen it happen. Then again Ive never had a floor shrink either. The glue dries alot quicker and its alot less mess if you have to pull up a plank.
Rolling glue (Pressure sensitive) will give you much better stability. First you need to understand how glue works. Wet glues like acrylic (f44) is designed for you to lay into wet and then a heavy weight roller will compress the glue trowel marks that will create a suction and pull the vinyl down. This is why we put it down with a trowel and pre-set trowel blade size. If the adhesive is left to long before laying the vinyl/lvt the adhesive wont compress and will result in showing through the material in a few months time. (adhesive grin) Dry glue (pressure sensitive f46) is laid into when its dry. As its dry you cant squash the trowel ridges with a heavy roller. Instead the LVT will stick to the ridges of the adhesive. With time the adhesive will show through the lvt as your point loading the flooring. (bit like a stiletto heel compared to a flat shoe ). This is known as 'adhesive grin' . Also (the main point) if you are now sticking to the trowel ridges you are only actually bonding maybe 10% of the product? Your product will also be able to move side to side on the flex of the adhesive ! So we roll the adhesive flat with a thin hair paint roller. Now your product will have almost 100% contact with the adhesive. Also as the adhesive is now 'flat' you should have very little side ways movement so less chance of gapping with heat change! So why put down PS with a trowel and not just a roller? You are using the trowel to simply apply the same amount of adhesive to the subfloor, not to thin and not to thick.
I'm going to take a guess here and say you have never taken the subfloor temp or the LVT's temp before laying? After all, why should you? it doesn't say you should in the fitting instructions! Going on from my assumption , i think it will be pretty much impossible to know if the products you have fitted are hotter or colder. Yes you may and i may presume by feel etc that one is hotter than teh other etc, but without something to tell us the difference we are only guessing. Random example for you- why would we have a speedo in our vans if we as humans could judge things so well? Well we cant! Getting back to your question. "If the material its made of changing from time to time?" Well yes it does change. But it should not affect you as a installer. Its plastic at the end of the day. Its effected by heat. Going back to what i say about fitting at the correct temp you wont have a issue UNLESS - UNLESS- you can have problems with LVT's when they are not manufactured properly. If you look at a LVT it is made form 3 or maybe 5 layers normally. So this is where the issues can happen. 'Tenting' being one of them! For the LVT to lay flat then all 3 layers would have to be bonded at the same temperature. So if something was to go wrong and the 3 layers was stuck together at different temps, well the LVT will change its shape. It will 'tent' for instance, or if it was glued together with one end warmer than the other it may want to bow at warm temp. Anyway, im not going to get technical and start confusing you all, but im sure you get teh idea.
No I dont ever take the temp of any floors to be honest but I have definatly fitted warm lvt onto cold screed with out it shrinking? I guess it doesnt always happen? If I was to take temp readings how am I supposed to know what temp is suitable for each type of sub floor and each type of lvt or should they be the same temp or a certain amount different?
There is no rules written on temps that you should fit LVT. Infact the fitting instructions for LVT's are wrong! They say acclimatise? Do they mean acclimatise to the conservatory that happens to be 40c as its mid summer or acclimatise to the winter conservatory with no heating at -10c? I can only 'advice' you ! Well that is until the day that manufactures change there instructions. Im on the case tho and im sure it will happen soon! Basically you need to install the product maybe 2c colder than the rooms average temperature.
Fitting warm LVT on cold screed doesn't mean its going to shrink as a whole job. Your speed of fitting will have a impact on the shrinkage. If the product is shrinking as you fit (the cold slab effecting the lvt) your flooring is getting smaller as you fit. You may fit the area without realising it was shrinking as you fit. Try this. Measure a plank of LVT. Make sure you do this accurate. Now, stick it in the fridge and measure it. next stick it in the sun and measure it. You will see for yourself just how much it can change its size with temperature.
