On Sun, 01 Sep 2013 11:34:47 +0100, Roger Mills wrote:

On 01/09/2013 09:35, Mark BR wrote:
Have heard about screws that you drill a pilot hole and screw directly into
a concrete floor - no raw plug so ideal for fixing floor boarding, skirting
and the like.

But I can not find them in either Toolstation or screwfix in less that 75mm
lengths - all described as for frame fixing.

I only want to fix 22mm floorboards to a concrete floor so am looking for
something about 45mm or so.

Any suggestions?

--

Mark BR



ICBW but I'd have thought that you needed them to go into the concrete
by more than 23mm in order to hold firmly.

Same here - thinking about the springiness of floorboards. Even if hard down
on a solid surface, the give in the wood and repeated compression will have
an effect.
Screws are only a friction fit (in the Antarctic, the buildings are bolted
together as the thermal cycling loosens screws).
Some of the reviews mention that the 'thread' in concrete won't survive many
removals/replacements, so I'd go for a longer screw for more insertion - er,
what's the subject? - for strength in the thread as well.
--
Peter.
The gods will stay away
whilst religions hold sway