Urgent advice required: how to find floor level

[kjacko]

Hi all,
I’m using stopgap 1200 pro to level an approx 10sqm kitchen floor, but where do I start the pour? I’m expecting the smoothing layer to be up to 10mm deep in some areas, but can’t be sure because I don’t know where the lowest part of the floor is as it’s quite undulating. There is a rise in the middle of the floor along one of the 4.2m long walls as there used to be a chimney breast there, but not on the other side.
My laser level doesn’t help very much as I can’t get the horizontal line low enough to meet any part of the floor for me to gauge the level. I don’t have a perfectly straight edge long enough to span either the 4.2m length or 2.2m width.
Would it better to start at the perceived high point in the middle and let the liquid flow to the lower points?
Hope this makes sense enough for you guys to advise ASAP as I’m wanting to get this done this weekend.

many thanks

 

[Mr Chibs]

If you can clearly see there are high points before you start, you need to sort this before you pour.

What is the floor currently made up of?

Not familiar with that product, but assuming it's acting as a self levelling compound... I'd start at the furthest end from the door, and pour in sections and use a trowel to push it around, working backwards towards the door, if you've got the floor in a 'flat' state before you start, you shouldn't have any problems.

 

[foxhole]

Mount laser level on wall 1m above floor and use a stick with a 1m level marked on it and move around the floor to compare .

 

[kjacko]

Ok, got this sorted now guys thanks.
The far end of the room was the highest point, but to level the rest to it would mean bringing the near end up by well over an inch and above the actual outside door threshold (which I’d already raised when I first saw the state of the floor, but not enough obvs.).
So.....the far end, the floor is made up of concrete slabs for about a 3rd of the length of the room. Across the span of the 6ft slabs there is a difference of nearly 20mm in level. These were the cause of the problems. The neighbour, an ex builder knew all about the subfloors etc so we ended up smashing the slabs out and tomorrow we’ll replace with a screed but level it off so that it’s nearer the level of the far end. After checking with my laser level it will bring the requirements for the SL compound in line with what we want, so all is good.
It’s a learning curve.....a steep one, but still, all good.