Monthly Archives: July 2015

Sunken bath?

Baths have a very common problem:
When full of water and person, the weight is very substantial and this often causes the bath to settle slightly over time which in turn causes the sealant around the edge (where the bath meets the wall) to be stretched slightly and fail.
The common way to address this is to fill the bath before the edges are sealed (or resealed), and leaving the bath full until the sealant has fully cured (often 12 – 24 hours).
However, this is not really getting to the root of the problem.
Suspended floors on the first floor of many houses are commonly timber construction and over time this can ‘sag’ leading to the floor to slightly resemble an old trampoline.
This will be evident in two ways:
Firstly, a gap will often open up between the skirting board and the floorboards of maybe 5 to 10mm
Secondly, items placed around the perimeter of the room, such as wardrobes, will show up the floor’s sagging by leaning away from the wall towards the top.
This is why wardrobes and such need fixing to the wall at the top and/or propping with small wedges or blocks under the front edge.
So given this tendency for a floor to sag, it is hardly surprising for a heavy bath to pull away from the wall leaving a gap around the tiles or wall at the bath lip that is similar to the gap that occurs between a floor and the skirting boards.
While this gap can often be closed subsequently by removing the bath panel and ‘jacking-up’ the bath by adjusting the threaded feet that support the bath, it is still not the best solution in my opinion.
Whenever I fit a bath, I fix a wooden batten (using 2″ x 1″ PSE timber) to the wall around the wall edges at the exact height required for the bath panel to marry up.
Because this effectively supports the bath lip at the wall, it remains immune to any problems of the floor and a gap never opens up regardless of the bath being full or empty.


Fixing to a wall.

Many times you need to fix something to a wall and the most common poorly-fixed thing is a curtain pole.
Internally, a wall will generally be either:
a studded wall
— usually a wooden frame covered with plasterboard and often between rooms
or else an external or supporting wall
— often of brick but maybe built using lightweight blocks and usually plastered or dry-lined (i.e. covered with plasterboard).
In almost all cases, a fixing for something heavy needs to get into the brick or block of the actual wall since fixing into just the plaster or plasterboard covering is unlikely to be able to take much weight.
Note: For a studded wall you need to find a wooden vertical or horizontal part of the frame to screw into.
Invariably, this means that the usual 20mm screws supplied with your curtain track/pole will be almost useless unless they are screwed to a wooden batten you have previously fixed onto the wall.
The reason is simple, the depth of the plaster applied to most walls will be in the order of 10mm or more so less than half the supplied screws will be going into anything of substance.
If the wall is fairly modern it is likely to be dry-lined with plasterboard which is literally stuck onto the wall using dabs of adhesive. This method also creates a small air gap behind the plasterboard which means if your wall is dry-lined the average 20mm screws are unlikely to even reach anything of substance like brick.
Firstly, you need longer screws probably in the order of 3” — which is about 75mm.
Recognise that, as discussed above, the final 20mm of this screw (as screwed) is not doing much ‘fixing’ so it will be the first 50mm of the screw that needs to get into the brick or block beyond the surface plaster or plasterboard.
Using a hammer drill and a masonry drill bit, drill to the depth of the screw taking care not to enlarge the hole by poorly supporting the drill while you are drilling.
Note: The drill should be kept in line with your hole at all times.
Generally, a 7mm drill will be most suited to a screw of 75mm sizes and will commonly use a brown wall plug.
Note: A 6mm hole often needs a red wall plug and a 5mm hole often needs a yellow plug (colours may vary by manufacturer).
Now look at your 75mm screw — it has a point, then a threaded part and then quite possibly a shank (which is not threaded) before finishing with a head containing the driving slot, Phillips or Porsidriv socket into which your screwdriver fits.
If you think about it, there is no use drilling a 75mm hole through plaster or plasterboard into the brick beyond and just poking a wall plug of say 50mm length into the first part of the hole. This is because only half of the plug is into the brick where it needs to be. Furthermore, the shank of the screw which has no thread could be within the plug and you really want the plug to be filled with threaded part of the screw.
So using the screw as a drift (a punch) get a small hammer and drive the plug into the far end of the hole. When the plug comes to rest at the far end of the hole there should still be about 50mm of the screw showing and waiting to be screwed into the plug you have just delivered to the far end of your hole.
Now put the screw, through the thing you are fixing and into the hole allowing the tip of the screw to find the central hole of you plug.
Now tighten carefully.
Two final things:
1) If the thing you are fixing has any thickness to it then this thickness reduces the length of screw available to go into your plugged fixing hole so add this onto the chosen length of screw employed.
2) The plasterboard on a dry-lined wall is perfectly capable of being squeezed against the small air gap behind the board as you tighten the screw. Hence, the thing being fixed will break or crush the board around your hole if you over tighten the screw.
For really heavy fixings to a dry lined wall you will need to address this ..but how is another story.