Tile over wooden and concrete floor?

[Richard C]

I tried to private message you but it looks like I can't.

Only possible if we are friends; I’ve sent you a friend request.

Getting a Corgi gas guy to run the gas pipe and then wrapping it in denso before dropping the ballast?

It’s no longer called Corgi, its Gas Safe & you must get a registered fitter to install, test & certify the gas run; I doubt any registered Gas Safe fitter would dare risk signing off DIY work.

Ideally I should be putting this part into a break out duct with granular vermiculite. Can I ask how to do this please? Is it difficult?

The ducts are formed in the over site ballast using a suitable former (could be greased timber) which is removed once the ballast has set, the pipes are laid in the duct, pressure tested & the duct filled with Vermiculite granules, the screed is then laid over the top. If you are going to use insulated backer boards instead of screed, I would just lay these over the top of the ducts.

I guess with the radiator I can do my own solders and then check for any leaks before denso taping it and then also putting it into a break out duct. Will the radiator copper pipes not expand/contract and burst?

No, they won’t burst with expansion & contraction, only if the water in them freezes.

Would you use 50 or 100mm denso tape fir the 15mm pipes and is there a technique for applying it? Does one coat do the trick?

Just wrap it around the pipe; 50mm tape will be more manageable on thin copper pipes.

Lastly, an electrician has cone up with a plan for me to take care of the wiring so I can drop the ballast in. He's going to come back at the end and connect the new kitchen ring into the consumer board and check it/sign it off.

A kitchen is a special location &, strictly speaking, he cannot sign off someone else’s work; all he can really do is do a PIR & sign off the results of the test which is not the same as a minor works certificate which you need as regulations go. It does happen but I’m surprised he’s agreed to do that, if he gets found out he runs a risk of being prosecuted, loosing his registration & his livelihood.

My question is... how do I run these cables? Through the ballast or under the DPM or how?

I’m unsure of the regulations regarding running cables in solid floors; unlike walls, they don’t seem to have defined safe zones. I suspect that they should be laid in conduit (or you’ve no chance of ever replacing them) & at least 50mm below the surface for safety. Personally I would follow the more conventional route & run the new cables in the celing & drop down the walls within the defined safe zones;
http://wiki.diyfaq.org.uk/index.php?title=Safe_zones_for_electric_cables

 

[chriselevate]

Hi Richard,

Thanks for your help.

So break out ducts with protected copper in (denso tape do the trick) then filled with vermiculite and then the screed over the top should to the trick? You mention using timber in order to make the ducts? Is this the way to do it?

I'm doing my ballast at 80mm so wondered how to go about this. Do I drop the timber in, drop the ballast in and then remove the timber? What sort of sized timber are you talking? Would you run one of the radiator pipes in the same duct as the gas the plumber does? I phoned a new plumber today and he said the same as you... "I'm gas safe as gorgi registered is no longer the way it works".

With the electric I hear what your saying but I guess people do lay the cable under the DPM and then where it chases up the Walls it goes into ducting and into the back boxes with a gromit protecting the cable? What do you think?

 

[Richard C]

Have replied to your PM.

 

[chriselevate]

Things are REALLY picking up and I'm now back cracking on with the floor!!! Hurraaayyyy!!!!!

Sounds like the "marmox" will work well if I don't have the ballast perfectly level (it's going really well though)? Obviously after it has strengthaned and dried out fully I can then cut this board easily and then lay it?

Does it provide much insulation? and can I put synthaprufe down before laying the marmox? If this needed or worth doing?

Are the boards expensive? Easy to get? Looks like my merchant are a stockist (I have a cash account there) - don't know if they would have them in stock or a special or though.

Thanks again

 

[Richard C]

The level of insulation provided depends on the thickness you use; 10mm has a u value of 2.7, 50mm u value of 0.54.

If you are laying a DPM under the new floor & at the edges as I posted previously then you don’t need a second Synthapruf barrier. Marmox boards are fixed using a thick solid bed cement powder flexible tile adhesive, if you put Synthapruf is bitumen based, if you put that down the tile adhesive probably won’t bond to it too well. Do not lay the boards until the ballast has fully cured & dry - 1mm of thickness per day.

If you Google Marmox insulation boards, you will find many on-line suppliers.

 

[chriselevate]

Awesome! Thanks for this Richard! Makes sense!

So I need to calculate the thickness to go on top of the ballast in order to give me a level floor of desire compare to the rest of the house etc? What would you allow (size wise) for the board adhesive, the tiles and tile adhesive in the calculation?

The boards won't run under the units will they? Is that just wasting money?

Thanks again

 

[Richard C]

I would advise you lay the insulated backer board over the entire floor area, it’s certainly not wasting money. If you’re using 50mm, it’s going to be very difficult to accommodate such a difference in floor level when installing the kitchen & you will also loose much of the benefits of laying the insulation if you don’t have it over the entire floor.

Both the backer board & tiles should be laid in a solid thick bed adhesive which will be 3-4mm thick so that will be around 7-8mm + the thickness of your tiles. Use a trowel with 20mm round notches, 10mm deep, at 28mm centres.

 

[chriselevate]

Fantastic Richard.

Thanks. I guess the thicker the board the better it will take litany floor discrepancies? Or is but really the case? Is it just the thicker it is the better the better the insulation? I'll notice the difference between a actress's floor with no insulation and using the boards? It'll be a lot warmer on the tiles?

Do the boards need to but up to each other perfectly?

The are parts where the ballast has come very close to the top of the DPM (I tried my hardest to have a good overlap but struggled in a couple of places) shall I synth it or leave a few mm gap next to the wall? I've worked out that I need to hack off render and damp inject so the walls are going back to brick in these places anyway. Wish I didn't have to inject but I think that'll be a sure way to STOP these solid walls taking in damp! So annoying!!!!

Thanks for this

 

[Richard C]

I guess the thicker the board the better it will take litany floor discrepancies? Or is but really the case? Is it just the thicker it is the better the better the insulation? I'll notice the difference between a actress's floor with no insulation and using the boards? It'll be a lot warmer on the tiles?

Makes no difference but the thicker the insulation, the less heat loss there will be.

Do the boards need to but up to each other perfectly?

Yes butt as close as you can; not so critical around the edge of the room except at the door threshold.

The are parts where the ballast has come very close to the top of the DPM (I tried my hardest to have a good overlap but struggled in a couple of places) shall I synth it or leave a few mm gap next to the wall?

Synthapruf it but only where you have to; bear in mind what I said about the tile adhesive.

I've worked out that I need to hack off render and damp inject so the walls are going back to brick in these places anyway. Wish I didn't have to inject but I think that'll be a sure way to STOP these solid walls taking in damp! So annoying!!!!

I assume your talking about a liquid damp course in the wall brickwork? This should be at or below the level of the DPM (or where it comes up inside of the walls) otherwise damp from the walls will transfer across into the side of the ballast/screed.

 

[chriselevate]

Hi Richard,

Again thanks so much for the help and advice.

Good news... I've got the floor in now!!! All 3 ton of ballast and 18 bags of cement! Gosh I'm shattered!!! The only problem is that if think there are dips in a few places and a few parts where there are a few wood depressions where I used a piece if timber to tap it down =( This being the case what would do about it?

Level it with something before putting the boards down? It's also 3 sections as I ran out of time and materials yesterday. In other words it's 3 sections... 1 was laid 2-3 yrs ago, 1 laid on Thurs and 1 laid this afternoon.

Thanks for your help.

 

[chriselevate]

Any ideas how to resolve the problem of the ballast not being too even? Now it's starting to dry and I can walk on it I can tell it goes up and down in places and there are a few placed where the wooden batten I used to tap the ballast down has made a dip in the surface =(

Any suggestions as to how to get the surface nice and flat/level ready to tile in a few months when fully dry?

Thanks

 

[joe-90]

You were supposed to finish the concrete 2 inches lower and screed the top 2 inches.

Don't know why you've gone to all that effort anyway. Ditra matting would have sorted it.

 

[chriselevate]

There was an original piece of ballast in thekitch that was done to this height already so had to bring the remaining 2/3rds of the room up to it.

Any suggestions to bringing it flat?

Thanks

 

[joe-90]

You can screed out the hollows (or levelling compound if it's too thin for a screed). If the high spots are too high you'll have to either grind them off or use a big sds hammer drill.

 

[chriselevate]

Ahhhhhh great!! Thanks for the help!

Levelling compound can be very thin then? Just so it gets it pretty much ready to lay tile board (such as 6 or 10mm marmox board) down on a 4mm flexible adhesive?

Where can I get levelling compound? Is it easy to use? Good stuff?

Thanks