Re: fitting loft ladder and flooring loft
Geegee said:
It is a new house and there are two layers of insulation - one between the joists and the other on top in a wide roll. The top layer seems to have imprinted itself onto the top of the joists so I was thinking of cutting it and pushing it down between the joists on top of the bottom layer - less materials and labour than fitting new wooden supports?? What is the most suitable tool to cut insulation with and what sort of gloves should I wear?
The new supports are mainly for the situation where you have existing pipes or wires running over the top of the joists, otherwise you may be able to lay your new flooring directly on top of the joists. It is worth having a look under your top layer of insulation, just in case it is hiding any pipes or wires which are lying across the joists. I guess it'll be down to the whim of the builders, electricians, and plumbers, as to whether things are lying across the joists or routed between, or through, the joists - in my case, some of the original wiring for the lights was running across the joists, and the pipework for a newly fitted electric shower also ran across the joists. I briefly considered gouging out small channels in the joists, so that the wiring would lie below the level of the top of the joists, but I quickly ruled that out as I wasn't sure at what stage I would be affecting the soundness of the joists themselves.
If you are considering laying the new flooring directly on the joists, and pushing the top insulation down between the joists to facilitate that, bear in mind that if you compress the insulation you may be reducing its insulating effect. In general, I believe that insulation is most effective when it is fully expanded. If you squeeze both layers of insulation down between the joists, you may end up with two layers of insulation which are doing a poorer job than just a single, fully expanded, layer. Your best bet would be to look up information on the insulation that you have, if you can find out what type it is, to see what its optimum thickness is. Getting maximum benefit from your insulation is another motive for adding new supports across the joists, if the insulation requires the additional height for best performance.
For cutting the insulation I started out for a Stanley knife, but found the blade too short. I then resorted to a sharp kitchen knife, and that worked (it may not be the best thing for the blade though, depending on the insulation material you use, so I didn't reach for any decent kitchen knives, just one that I was willing to risk). Ultimately I ended up using a sturdy scissors though, as that was a little easier. The insulation that I used is Pink Fibre Glass Insulation ([broken link removed]) - it is actually glass fibre (which I had forgotten), but it is much finer than the heavier and more scratchy yellow stuff that I have encountered before. It expands to 6 1/4", which was ideal for the space created when I added new supports. I bought it in Homebase at the time (several years ago). If your existing insulation is okay, then that'll safe you some cash and effort, otherwise I found this Pink insulation to be very good.
As regards gloves, I started with garden gloves, but found them too restrictive, so I ended up using standard kitchen rubber gloves. For the insulation that I was working with, even finer gloves would have been adequate, so next time I'd used something like nitrile gloves or vinyl gloves (I deliberately avoid latex gloves as apparently they are increasingly found to be problematic for people with sensitive skin).