mastic

So I just had a new chipboard floor glued and screwed in after adding noggins and levelling the joists. There are gaps between the edge of the chipboard and the blockwork, up to 15mm. There is a gap between the dot and dab wall and the new floor of up to 40mm high amd 30mm deep and also the void...

I know what slicone is. But mastic, what is it? How do you define what a mastic is, and why might it be used and not silicone?

Hi, I have a basement room which runs below the steps to the main entrance (see pic). This has been there for years. Every couple of year we have been painting the steps with bituminous mastic as the waterproofing fails and water makes its way through. Has anyone got any tips or advice as to the...