Karndean uneven floor height (help)

Hello and happy new year to all, thank you for reading my post.

I am sorry if this has been asked before, I did check the forums. New to forum and looking for some help/advice.

I have recently had a an extension built to the side of my house. I decided to have underfloor heating in the new section in addition to the existing lounge area as the wall was being knocked through. I decided to keep the rest of the house without UFH due to costs spiralling.

I am also having Karndean laid across the whole ground floor. The problem I have is the
screed (Cemfloor) is down in the new area, It was laser levelled and I was advised I needed 90mm. We have discovered our existing floor is not perfectly level, there is a 30mm gradual difference from the front of the house to the back. It basically slopes down to the kitchen. So the new floor in the snug room is 30mm higher than the old floor in the kitchen diner there is a door way taking you from one room to the next. Both areas are having different versions of Karndean.

I’ve blown my budget and not sure how to resolve the height issue, will I need to screed the kitchen diner or can I use a step down transition? Or even some simple self levelling compound.

Thank you in advance for your help.

 

HI and welcome, sounds like you need someone to pop over and have a look at it. Whereabouts are you and someone on here may help

 

Hi Mani and happy New year to you. Is the subfloor in the kitchen concrete? Making a floor level is going to be expensive and do you have the heights to play with at doorways etc? It maybe easier to work on a room by room basis and have a break at the door threshold. You will need to allow for a movement joint in the vinyl where the heated areas meet the unheated areas to allow for thermal movement. I would have someone take a look at it as the above member commented. Also be mindful the Cemfloor is an anhydrite screed and needs to special consideration for moisture testing and also a suitable smoothing compound has to used.

 

Thank you both for your replies. This is getting more worrying for me the more I think about it. I wish I had just stuck with carpet now or just a normal tiled floor.

I live in Walsall West Midlands.

I don’t think the Cemfloor is anyhydrite, I think it is a cement based screed.

 

Thank you. I am in Walsall, West Midlands.

 

My builder has suggested lifting the tiles and then putting down some self levelling compound in order to bring it to a workable height, he admits that he has never installed Karndean and does not know too much about it.

 

Sorry, I forgot to say, yes the existing floor in the kitchen is tiled and has concrete under that, below that is block and beam with a thin layer of insulation. It’s a 15 year old house built by George Wimpey at the time.

 

I would ask the builder for a data sheet on the Cemfloor as the preferred screed with underfloor heating tends to be anhydrite due to the flow around the pipes and the thermal benefits, 90mm May include the insulation. If the builder is not a floor layer i would go on to the contract flooring association website and put in your area and it will provide you with a list of installers.

 

I checked the data sheet and it seems to be fine in terms of thermal conductivity, it also flows in between the pipes, it was recommended by a number of screed suppliers, initially I was told I needed 60mm, however once it was laser levelled I was told I needed 90mm. Below that I have the DPM, Celotex 100mm insulation.

I can just stick to the Karndean in the heated new area and just go with tiles instead of Karndean in the rest of the house. I really cannot afford any extra costs. I will check the website.

Roughly what would it cost to level the rest of the house, kitchen diner is around 30m2.

 

Cemfloor is a cement based liquid screed. Should dry quicker and less laitance on top. Liquid screeds can go thin but that doesn’t mean they won’t be poured thick.
Put in thresholds to keep the cost down or use levelling compound to get the heights right. You defo need a flooring specialist for this job, not a builder!


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Do NOT let your builder do the karndean else you will regret it - it will either be stuck with a crap floor or cost you alot more to put it right. Your builder had already told you he doesn't know much about it so surely that days it all.

If you can't afford to do it properly then freeze this whole thing until you can afford it seriously.

 

Thank you all for your replies and advice, I’ve checked the web site and will give a few companies a call to see if they can come round and offer any advice and prices.

I would have thought Karndean would have been okay on a sloping floor once the self levelling compound had been added to where the tiles had been lifted.

I will leave it to the experts and hopefully it does not cost me too much more.

Thank you again.

 

Thank you. A little bit of relief, 30mm difference across 10 meters I’m hoping won’t show up as much.

I’ll hopefully get a reasonable quote to sort out the 30mm step from old to new.

Thank you.

 

that wont show up at all as long as it is done by a pro and is smooth with no dips and you do not have gaps under your skirts and achitraves, when people talk about level floors most go by eye (customers) you would need to be pretty anal to notice a slope in the floor if the entire floor is on a slope, most times it becomes an issue is when you have half the floor level and then the new bit of extention 'slopes' down as that then becomes noticable and an issue.

 

Quite easy to form it into one continuous smooth surface all be it on a slight gradient using fibre reinforced levelling compound and granite chips and would be virtually unnoiceable. Just make sure it' a flooring installer and not a builder that does it.
And have you asked the question why the builder didn' get it level in the first place?

 

Morning and thank you for the reply.

It’s my existing property that is not level, the new extension was self levelling liquid screed which could not be laid down at gradient, hence why it’s level to my existing floor at the front and there is a 30mm difference at the back of the property. Length of the property is around 10m.

 

So is this extension to the front of the property? . Could really do with some pictures and a rough sketch of floor area showing old and new areas before then arranging site visit?

 

We need pictures so we can advise accordingly