How to fill a large gap between walls and floor tiles?

KBdoesDIY

HI Team,

I have a large gap between floor, wall and tile floor where I pulled up old skirting board. It is deep, wide and runs the whole length of my laundry. The old skirting was sunk below the tile line.

My plan is to MDF the walls and install new cabinet and finish.

I see a few options.

1. Fill the gap now. If this is the right option, how? I'll be using dozens of tubes of silicone and days of effort on the caulking gun if this is the option. I read another of your solutions which suggested weather shield (https://www.bunnings.com.au/moroday-10mm-x-5m-white-gap-filler-rod_p4061881) first, then silicone. Still a lot of silicone.

2. MDF now and sink the sheets into the gap, then fill the gap, finish with skirting board over the top. Sounds easier except keeping the sheets up 5mm for the expansion gap at the bottom might be tricky. How would i do that? Also, I wasn't going to put skirting behind my new cabinets so there would still be a need to fill some gap.

If i put in westhershield, put the MDF on top, would that act as an expansion gap?

3. Something else?

Really appreciate advice. This was a little unexpected! I thought the skirting finished at tile level... not sunk below. Even getting it out was hard work.

MitchellMc

Welcome to the Bunnings Workshop community @KBdoesDIY. It's wonderful to have you join us and many thanks for your question on filling a gap.

If that gap is going to end up completely hidden behind your new cabinetry, there’s a good chance you don’t actually need to fill it at all. In that case, you can save yourself a lot of time and materials by simply leaving it as-is. If parts of the gap will remain exposed, though, then using a filler rod (like the Moroday gap filler you mentioned) is a sensible approach. Just push it slightly below the tile level so you only need a thin bead of silicone over the top, rather than filling the entire depth. That will drastically cut down on how much sealant you use, even over a long run.

Another option worth considering is a self-levelling cement. If the cavity is contained and won’t leak, you can mix a batch and pour it in to bring the level up more efficiently than using multiple tubes of silicone. It’s generally quicker and gives a solid base to work from. From there, you can proceed with your MDF and finishes more easily.

I've created the rendering below to illustrate how the gap filler rod and silicone should be used.

Please let me know if you have any questions.

Mitchell