Insulation challenge of a 1955 Bungalow

[uktricky]

OK temperatures have dropped and therefore reminded me that I should have improved insulation in house last year!!!

1955 Bungalow with a Lounge built over a garage and an open stair case leading up to a roof conversion bedroom. The bedroom has a radiator within but an area (landing) outside the bedroom door approx 3m x 2m has no form of heating.

Garage is large but a single with up and over garage door (with lots of drafts) and a concrete roof/floor. Should note that the boiler is located in the garage. Lounge is 3m x 7m with 2 large windows and 2 smaller windows built over the garage. There is NO insulation on the garage roof or between the roof and the joists to floor boards. The space between the two is approx 4" to the under side of the joists which I can see down from under the crawl space under the house. I therefore cannot access easily the space under the lounge.

Crawl space access within Garage (again with drafts) and a door approx 1m square. Leads to rest of crawl space which varies in height under the joist from ~1.5m to < 0.25m

Kitchen is incredibly drafty around non-fixed applianced (washer & dryer) and has a tiled floor. I can access the crawl space under the whole kitchen and the majority of the rest of the house.

I want to improve heat loss from flooring area especially in the lounge and kitchen as these seem to be the rooms which suffer badly for being cold.

Challenge 1 - Under the kitchen (3m x 4m) I have considered putting insulated boards (celotex??) between the joints but not up against the underside of the floorboards (is this OK to do?) and also perhaps under other areas without carpet I.e. Bathroom Floor (Varnished floorboards 3mx4m) and Hallway (Solid wooden floor over original floorboards 1.5m x 8m).

Challenge 2 - The lounge (carpeted) How can I improve the insulation of this floor given the challenge of the space between Garage roof and Joists. Considered trying to push rolls of fibre insulation down using rods but this would be rested on top of the concrete garage roof. Like wise considered Celotex type boards cut into strips to get through access space! again rested on garage roof. Would this be "acceptable" and likely to improve heat loss?

Also considering the replacement of the up and over garage door with a double glazed type unit to reduce the amount of draft as I don't use the garage for vehicles.

Any recommendations given the information above?

Read more: link to inferior forum removed. Mod 2.

[Perry525]

You have a typical badly build home, typical of
its time.

The first thing you must do is go round all the
doors, windows, ceilings and floors and seal any
gaps/cracks that you find.

Keep in mind that the passing wind creates a low
pressure area over the roof that tries to lift
the roof off - this pulls the warm air out of
your home, the warm air is replaced by cold air.

Blocking all the holes, is a quick way to make
the most of the heat that you are paying for and
losing. A quick fix for the floors is to cover
them with newspaper and sheets of hardboard to
stop the cold air coming through, use canned
foam or tape to fill awkward to get at holes.

Once you have fixed the holes and drafts then
move on to the insulation.

If you think about it, a Thermos flask is a good
example of what a home should be, a solid
container with no drafts and one usually sealed
opening. The flask relies on a vacuum to keep
the heat in, the only heat loss, is through the
neck of the flask by conduction.

We cannot buy or make a vacuum flask in the
shape and size of a room, so we have to make do
with the next best thing - insulation.

Start with the lounge.

To keep the heat in, the lounge needs to be
lined with polystyrene sheet. That means
covering the ceiling, walls and floors with
polystyrene. Polystyrene sheet is a mass of tiny
air bubbles held together with very thin
plastic, each bubble contains air which is the
best insulation available at a decent price,
polystyrene is warm to touch and is draft proof.

Start by covering the floor with inch thick (or
thicker) sheets of polystyrene, then cover the
polystyrene with Oriented Strand Board floor
boards, these need to be tongued and grooved and
stuck together with wood glue. You must take
care the the new floor does not touch anything
and is fully floating, gluing turns the floor
into one insulated monolithic piece, that will
keep the heat in the room. Fill the gap round the
floor boards with canned foam.

Then replace your underlay and carpet.