Insulation question, loft and walls, advice please.

Feel a bit miffed! Just had a survey visit from B Gas (after being booked in for 2 months!) for loft and cavity wall insulation. Was told already have 100mm ins in loft and therefore not eligible to have a top up installed for free, however can have an additional 170mm ins put in 2/3rds of loft for £199. Also been told cavity wall cannot be done because of cement “snotting”(his words not mine), only pockets of space for insulation to go to and would end up with damp areas in wall. My neighbor has had walls and loft done I think by BG I need to check with him in morning. Would it be cheaper to do loft myself? What insulation do you recommend and is it worth getting another company in to do walls? Experience / advice please.
Thanks.

“Snots” is a widely accepted term for them, and can be a problem with partial-fill insulation as you need a 50mm ventilation gap. However, pumped in, after market insulation is not the same stuff and is designed not to transmit water by capillary action (see Rockwool blown insulate). “Snots” should not prevent the installation of blown insulation, unless they regularly close off the cavity, which I find pretty unlikely.

Make sure they do under and above the windows as these are often areas that are missed resulting in cold spots.

I would definitely get a second opinion for the walls.

£199 seems quite reasonable for the loft, depending on it’s size, of course, but it is pretty easy to do yourself; just make sure you wear gloves and a mask and abide by the manufacturer’s laying instructions (you usually lay the upper layer so the joints are at right-angles to the lower layer joints.

do loft yourself – insulation was £3 a roll last time i bought it!

Just a wee tip if you do insulate your own loft. Make sure your water pipes are well lagged if they are above the insulation as u can get frozen pipes easily because you are retaining the heat on the room side of your ceiling creating a cold loft space.

Dead easy to do a loft. Always offers on insulation at the DIY sheds. It can be relatively unpleasant on a warm day in a tight space. Make sure you cover your skin, and wear a dust mask if you are using the mineral wool type. Goggles may help if it is a confined space.

Just a wee tip if you do insulate your own loft. Make sure your water pipes are well lagged if they are above the insulation as u can get frozen pipes easily because you are retaining the heat on the room side of your ceiling creating a cold loft space.

Good advice right there 🙂

Also, if you have recessed lights, make sure you fit fire-proof covers over the top and keep the insulation away.

Fitting insulation can be a messy, difficult job sometimes (it can also be easy) so maybe assess the difficulty before you finally decide whether or not to do it yourself.

Remember when you get out to the eaves, leave a gap for airflow between the insulation and the roof.

Blocking up the ventilation holes (assuming you have them) is a recipe for damp.

Oh and use rigid foam/kingspan etc on the top of the hatch with foam seals on its underside to prevent draughts.

insulation was £3 a roll last time i bought it!

Oh, how I wish it was that cheap now

Nice one thanks STW. I think I’ll do loft myself, needs to be empty as well so good time for a clear out. I’ll get a second opinion for walls to, as we are end of terrace the outside wall gets very cold, be really good to get it done. Bit annoyed with BG could have done this 2 months ago! Ta.