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Original poster

Self build extension

253 replies

Diyextension · 09/06/2022 00:44

Noticed a few threads on people building extensions / knocking down conservatory etc , so I’m just about to start doing mine.

I thought it might be good for anybody thinking about building one or for people that have no experience/ idea what the process involves.

i will probably be doing about 80% of the work myself , and then using certain trades , plasterer/ electrical as and when.

Old conservatory will be removed and. Single story (bedroom ) extension will be in its place. It’s 5m x 4m .

progress will be slow as I work full time so days of and holidays only.
it should be a straightforward job , but the only downside is we live on a hill so everything has to be carried up/ or down.

if anyone has any questions , feel free to ask and I’ll try to put pictures on as and when there is any progress.

Self build extension
Self build extension
Self build extension
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Thread gallery
172
DaisyDays123 · 15/02/2023 11:25

I don’t think you can put varnished wood in log burner 😮

Floppy12 · 15/02/2023 12:03

@Diyextension Its really taking shape now. Super well done, such a well organised well kept site as well, that is something I need to get a lot better at.

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Diyextension · 15/02/2023 17:50

DaisyDays123 · 15/02/2023 11:25

I don’t think you can put varnished wood in log burner 😮

Yeah well spotted , it wasn’t varnish it was mostly a thin brown stain, to be fair there were a couple of bits with paint on. But it was too much good , bone dry hardwood to pass on ., I just mixed it in with the logs and it was fine .

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Diyextension · 15/02/2023 17:52

Though I didn’t cut the roof timbers up , they will come in useful for something and the doors and frame were given away.

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Diyextension · 15/02/2023 17:58

Damp proof membrane went in , it’s almost impossible to fold the corners neatly!!!!! It’s so thick. There must be a knack to it but I don’t have it 🤔.

Self build extension
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Diyextension · 15/02/2023 18:04

Then the insulation….. just it time for it to start raining…. It’s amazing how much water collects when there’s nowhere for it to soak away to.☹️

so tomorrow I need to pop the insulation out dry all the water out that’s underneath it and go and buy a big enough tarpaulin to cover it until Saturday 🙄

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squtable · 15/02/2023 18:07

looks great!

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Diyextension · 19/02/2023 22:09

So dried all the water out (4 buckets full ) and covered it over ready for the concrete Saturday. Building inspector came everything was fine so all ready to go.

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Diyextension · 19/02/2023 22:12

Did a bit on the drains so it’s all ready to connect the gully up later when the walls are built and to get the drain covered up so I wouldnt keep tripping over it 😠

Self build extension
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Diyextension · 19/02/2023 22:22

So big day Saturday pump and concrete turned up on time and best of all the weather was mild , dry , couldn’t have asked for any better in February. Finally a a bit of good fortune with the weather.

it took all day to go off so I could trowel it up but really pleased with how it went .

Its been a lot of work in the ground and was hoping to get the groundwork done by new year, but that’s the hard bit done and soon should start to see a bit faster progress.

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TooExtraImmatureCheddar · 20/02/2023 15:28

Wow, I’m really impressed - following with interest because I’m trying to persuade DH we could do this too. My dad built most of his own house himself (also not in the trade, entirely self-taught), and I’m convinced we could manage a basic single storey extension. Keep posting please!

Rummikub · 20/02/2023 16:04

Amazing work!
do you work all day / all week on it?

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Diyextension · 20/02/2023 16:05

Thanks. Don’t be fooled into thinking it’s not hard work because it is and you’ve got to be really committed to giving up your spare time to work on it. To be fair my wife has helped when it’s come to shovelling, carrying , levelling concrete etc…. And has been a really big help when motivation has been a bit low. But technically it’s not too difficult to do/ arrange things yourself, anything I’m not sure of there is always someone to ask ,building inspector/ bricklayer , internet 😀.

Get your planning permission sorted and plans done and go from there.

here’s a picture of the concrete pump if anyone has never seen one. Quite a useful machine.

Self build extension
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Diyextension · 20/02/2023 16:07

No , only last week as I had a week off work, just normally on Sunday and my day off.

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Rummikub · 20/02/2023 16:09

Even more impressive then!

The other thing that confuses me is the ground level. It looks really steep and I presume awkward to work with

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Diyextension · 20/02/2023 16:16

Yeah, that’s the downside of living on the side of a hill, the ground around it will be all levelled off when the extension is done , so still quite a lot to do , but getting some stone down has helped and is keeping most of the mud away now.

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Diyextension · 22/02/2023 13:03

Did a bit more yesterday, seeing as it’s getting lighter till about half 5. …

finished the insulation in the cavity below the dpc. That’s to stop having a cold bridge and making the inside block colder ….

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TokenGinger · 02/03/2023 09:49

You're doing such a fantastic job. I'm really enjoying watching your progress.

Notyetthere · 02/03/2023 10:10

Loving this. Keep going.

I would like to be able to do this with a small extension to the back of our bungalow but with a 5 year old and an almost 2 year old and a husband who would probably think I am mad to even think we can do it, I will get my fix from watching you and others.

I follow Mr A Builders on you tube. He is charting the process from setting out, to building the foundations up to roof and internals. they are builders and they share the whole process in detail.

tanstaafl · 02/03/2023 13:01

Maybe as it’s foundation it’s different rules, but I’m sure I heard on the Skillbuilder YT channel once that the insulation shouldn’t be solid between the inner and outer brickwork.

reason given was if water gets through the outer brick it has a medium to get across to the inner.

BobBlack · 02/03/2023 13:16

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C4tastrophe · 02/03/2023 16:12

Do you need to fit a cavity tray on first course of blocks > down to external wall dpc because of the below dpc insulation?

Original poster
Diyextension · 02/03/2023 19:53

Thanks all.

I’ll try and answer a few comments and hopefully try and describe the process of the damp proof/ cavity tray and insulation as we build the walls.

@tanstaafl
The insulation you see in the cavity is below the damp proof course so the inner block is “damp” all the time. I suppose cold can still come up from below but there is insulation under and at the side of the floor slab to stop it bridging into the floor. Also styrofoam ( polystyrene) is waterproof so won’t be affected or breakdown in a damp environment.

Not sure it does all that much to be honest but I’m trying to insulate it as much as possible so I suppose every small thing helps.

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Diyextension · 02/03/2023 20:08

@C4tastrophe

yes that’s correct. You can buy preformed cavity trays, and that is what I intended to use but after a chat with the building inspector ( bricklayer said the same ). It’s better to use 1200 gauge damp proof membrane and form a cavity tray with it. So yes on top of the first course of internal blocks down and across the cavity and onto the outside damp course to were the weep holes are built into the brickwork.

That way if any water did come through the outside brickwork it would go down onto the cavity tray and out the weep holes and it couldn’t go into the inside skin because it’s higher on the inside than the outside.

it’s easier to understand it when you see a picture of it.

I’ll take some pictures in more detail when we are building.

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C4tastrophe · 02/03/2023 21:15

What will you use as cavity wall insulation?
When I was bricklaying I saw all sorts including rockwool, polystyrene sheets, foil backed PIR. Most required plastic wall ties and clips to secure them.
I’m not sure any of it will stand the test of time.
The ‘best’ houses appeared to be the ones with no cavity wall insulation, but 150mm internal (thermolite) block work and dry lining.