Patching up floor after wall removal

[mrjoe]

Morning all,

I've just removed an internal wall in my 1930s semi, the floor is suspended on rafters and they are resting on what is left of the wall. I want to fill the scar with mortar to create a level surface to lay laminate but there is a vertical gap of about 20mm from the top of the remaining wall to the bottom of the floor boards and in some places the floorboard are sort of the wall leaving a 10mm horizontal gap. See photos below (obviously I'll clear out the debris first).

My question is:
a) Do I need to put something in or under this gap to stop mortar falling down? If so what would anyone suggest? I'm thinking of just doing a fairly dry mix and it should be all right?
b) Either way what would be a good sand/cement mix for this purposes.

Many thank,

Joe

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[mrjoe]

OK so I'm a beginner at this building game when I said mortar I think I meant concrete.

Can I uses builders sand and gravel or do I need sharp sand?

Nothing is ever as strait forward as it first appears

 

[maltaron]

I assume the "scar" you mention is an old fireplace, in which case have you safely removed the chimney breast? and confirmed that the wall you removed is not load bearing. If that is all OK you should be screeding the whole quarry tile floor level with the boards, if you only patch the scar there is no other way to get a surface for laminate. Check the plastering section of this forum for screed mixes.

 

[mrjoe]

The wall was load bearing but not structural, BC have been round to look at the installed RSJ and are happy.

Tiles are pretty level, about 3/4" thick and don't come up easy! They are also slightly higher that the boards, not a disaster as the whole area where the wall/chimney used to be will have kitchen units on it. So the un-level bit will be hidden. Surely fibreboard underlay would be easier than screed and I can used this on the boards too?

The fireplace should be easy but for the wall do I need to put something in or under this gap to stop concrete falling down and what would be a good mix? (preferably one that used builders sand as I've got a load of it)

 

[geraldthehamster]

The fireplace should be easy but for the wall do I need to put something in or under this gap to stop concrete falling down and what would be a good mix? (preferably one that used builders sand as I've got a load of it)

A bit of squirty foam would fill the open gap, then you could level it up with concrete or whatever.

Cheers
Richard

 

[maltaron]

I understood that the floorboards were 20mm above the quarry tiles and needed screed to make up the level, obviously wrong thinking. Shame those quarry tiles do not cover your entire kitchen, they are the best kitchen floor you can find. Your fibreboard underlay should be fine but as the quarries are unlikely to have any dampproofing underneath it may be worth considering a paint on liquid damp proof membrane under the fibreboard.

 

[dhutch]

A bit of squirty foam would fill the open gap, then you could level it up with concrete or whatever.

Really?