So today we have fixed the floor, from underneath using expandable foam.
Not sure if its 100% success yet but so far so good.
Here the process I carried out, I'm not saying this is the way to do it nor am I saying that everything I say is 100% correct. If anything is wrong please feel free to put in your 2p worth.
It cost me £10 not the £25 + pp for a delam kit on the internet and £45 my local caravan centre wanted. On top of this to do the job from underneath I would also have needed a special glue gun which is another £40 + pp
Floors are constucted of 2 sheets of ply with a layer of polystrene foam sandwiched between. Delamination happens when fat gits like me always tread in the same place and squash the foam layer. eventually the ply pulls away from the foam (delaminates) and leaves a void which will grow and spread if left.
For me the area was outside of the toilet and where you step down from the seating area at the back of the MH
First off I marked out the full extent of the area with chalk and measured it
Then I transferred this plan to paper, not pretty and not 100% accurate. The important thing for me is that I know where the air vents are in the raised floor and I know where the hole is for the fire, these were my base points when under the van
Inside the van I then placed a piece of wood over the area and added some weight, this was not enough I had to add my tool box and a full 13kg gas cylinder later as the floor started to rise when the foam expanded. I thought about asking Nic to sit on it but why ruin a good day.
Under the van I transfered my drawing using the vents in the floor and the hole for the fires as base lines
Then I marked out 6 places to drill my holes, The hose of the foam injector should be a tight fit, I used an 8.5 mm drill bit.
Next drill your first hole very carefully through the wood, its only thin. I then removed the drill bit and by hand drilled up through the foam until I touched the underneath of the floor.
I then pulled the drill back about 1/4 inch and wound tape around it at that point. This is too ensure that you do not drill through into the hab area
. In fact I only drilled through the wood and then by hand drilled out the foam.
Next is the fun bit, stick the pipe of the expanding foam into the holes. Squirt and stop Squirt and stop as soon as it starts to come out of the hole next door stop and push in a plug. I left the 1 in the middle of the worst area until last. By the time I got to it foam was oozing out good and proper. Let me tell you if the devil had a cold this would be his snot. Its foul sticky stuff that gets everywhere once spilt. I did not wear gloves and I will regret it all week. I also have a sticky patch under the van that will need cleaning, I had paperdown but it missed, on the plus side its very sticky so once set I recon its going to do a good job of sticking things back together
Expanding foam goes in as a liquid then reacts and expands so you need to have 6 plugs ready to put into the holes. They need to be a tight fit or they will be pushed out. The last one I left out for a little while to allow the excess foam to escape, if I had not done this I'm sure the floor would have ended up with a bulge as it was I needed to add more weight inside as it began to lift the water bottles.
Hope this helps those that want to try this method. I'm fairly sure you could do similar with the proper kit but you would need to find some way of pumping the stuff in, the correct gun is £40 + pp on the net.
I'll report back on the finished results. One thing I'm wondering is if this foam is man enough or whether it will just crush when stepped on. You can also get a similar product but its a 'filler' this might be the stuff thats needed, I'm willing to drill out the holes and try again if its failed after all the holes are underneath so its not a case of pulling up the floor again.
