13 x 5m x 135mm Aerolite rolls needed.
Got a quote supplied and installed.
2 adult kids (brother and sister) R500 each, saves me R1000.
Seeing them work together … Priceless.
How long did the “hired” labour take…? Any issues you can share…
First roll was tough to, 2nd one easy:
- Challenge One: Get all the wires above the insulation.
- Challenge Two: In the middle of the roof their is a beam, insulation must go under it.
- Challenge Three: Beams are 1.1m apart, it helps if your son is a trained fit stuntman. Daughter who said she can do what he can do, yeah boet, she got a real big “workout”.
She made the mistake of saying: Geez, this roll is heavy! (getting it from beam to beam not touching the PVC ceiling.)
Son replied: Men don’t complain over shiite like that, toughen up buttercup and get moving!
… I nearly fell off the ladder laughing! 
Tricks we will learnt:
- My sons idea, we use thick planks to kneel on, sit on. Keep them near the trap door for easier getting in. Got the idea 12 years ago when we pulled the UTP wires in. We use 2 planks, one to sit on, when moving the 2nd one forward. Safer too. Less strain on the body.
- The part to get a 5m roll under a beam … roll it to the beam, then cut it, roll the rest of the way.
- Do NOT do it when the sun shines … no need. You need a touch in any case.
Now the next 11 rolls can come …
With temperatures dropping again in the City of Gold I can confirm that the insulation works. We didn’t turn the gas heaters on tonight.
Also SWAMBO found the shower water too hot tonight. Which goes to show that geyser blankets don’t last forever either (they reinsulated the geyser and the hot water pipes).
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Can also confirm we have a increase of between 3-5 degrees inside the house (compared to the house under the slab) since we installed the insulation Sunday.
Next is to find where the draughts are …
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This is great to hear. I can barely type this properly as my fingers are still semi-frozen after this morning.
You went with Eco-insulation, right?
I was in the roof over the weekend moving a cable and took a look and it also looks like almost all our insulation collapsed. And a part where the heat pump installers lifted insulation out of the way and never returned, so I also have a bathroom without any insulation which explains the extra cold seat in the mornings…
Have you guys tried Knauf Insulation? It seems to be one of the most popular insulation products. I got multiple quotes from different companies and the 135mm Knauf was recommended the most.
Anyone have it installed?
I like 135mm Aerolite - and for the price.
Look at the R-value, the key comparison in my opinion:
https://knauf.com/api/download-center/v1/assets/2757811b-41ba-43f1-9a49-7e827a1c49e1?download=true&country=za
Polysterene cutters in Pretoria sells bags of polystyrene balls for Roughly R150. Its really big bags and used for in ceiling insulation a lot lately. Look at the option as the prices is realy good
I don’t think you can use just any polystyrene for insulation, it has to have flame retardant added, otherwise it burns way too eagerly. So you cannot really use just any scraps, it has to be the specific kind for insulation like isover.
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Indeed. If unsure, put a bunch of it in your braai and set it on fire (but don’t try to cook meat on it, obviously). If it (the polystyrene, not the meat) willingly burns on its own, and then creates a little fiery river of molten stickiness… then it cannot be used in a ceiling.
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There are however products for that.
I once installed 8 x 110mm thick x 1200 wide x 2100 long Isowall boards as a “ceiling” underneath a low IBR flat roof.
Got them from this Co here, cut to size and delivered:
Worked like a charm.
Until you realize, in winter, you should have installed them right and tight or you will get condensation between the roof sheet and the Isowall, running down the Isowall to form nice little puddles on the floor.
They are flame restarted for safe installation - I tried to burn a piece with a lighter held to it. Did not become a fiery river of molten stickiness.
What worked even better in summer?
Painted the roof sheets white … after careful consideration of the reflection towards neighbours. Bad idea to get that wrong.
Holy smokes THAT worked for summers!!!
Just thought I share.
Ps. Eventually replaced the Isowall ceiling.
Had them cut in half, 50mm thick.
And installed them between Nutec sheets for a flat wall.
To be double sure, had one chance, also installed Radenshield between Isowall and 9mm Nutec boards.
Entire flat, and bathroom, built with Nutec.
Works like a dream … walls cold inside even with hours of direct sunlight.
Like those candles on birthday cakes
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The Americans have a rule of thumb for that (because they do a LOT of that drywall stuff over there). I think it is that the vapour barrier goes on the side that is warm in winter, otherwise you get condensation.
We accidently got that when we replace the roof yes.
Product called Alububble. It is a type of vapor shield too if fitted correctly. Now I know why they fitted it the way they did - the vapor shield part.
Can see white side of the Alububble in the first pic above the batons.
So underneath the Alububble, the 135mm Aerolite now.
Aerolite same R-Value as Knauf at half the price.
This the 3rd roof I’m doing. This one we got clever.
The Trick I figure:
Previous roof, had to cut the aerolite to fit over/between the batons, both roofs being flat.
This time … the batons in first pic, not screwed in yet. We could easily take them out one by one, put the Aerolite over the baton, push the baton back in position, then the screw.
Soooo much easier.
Before:
After:
With the white sheets to keep the sun reflected.
The Alububble underneath the sheets as a vapor shield and heat reflector back into the room.
Then 135mm Aerolite.
PVC ceiling to cover it neatly
Will see how this will works the rest of winter.
Third time’s a charm “they” say.
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That’s what I want - How thick is the PVC ceiling…?
Did it 135mm “thick”, measured from the roof sheets, for the aerolite to fit above it.
PVC ceiling itself … ±7mm thick.
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