Jump to content

Basic garden room insulated slab


daiking

Recommended Posts

Footings are poured.  I was too busy fannying about to get any pictures. The wench has some though.

 

Overnight temps of 2 degrees C ? should be ok...

 

-1 forecast tomorrow night...

Link to comment
Share on other sites

Forgot to say it was £130 for upto 1m3 of concrete and I had to pretend to poke and level it for free. 
 

He said I’m looking at about £200 for the slab when he comes back. 

Link to comment
Share on other sites

So foundation...

 

To go round my 4.15m x 3.3m foundation, I’ve calculated I need 32 standard concrete blocks.

 

Mortar wise, my research tells me that I want a 4:1 mix. 
 

I won’t need much 1 bag of cement should be plenty (+4 sand obvs). Other option is that a 20kg bag of ready mix mortar should be enough for 20 blocks so I could just buy 2 bags of that. Have never mixed mortar before. 
 

Apparently some lime or additive would be helpful as I’m below ground but for 32 blocks and a Wendy house it’s probably not needed.

Link to comment
Share on other sites

  • 2 weeks later...

I could have done with getting this done this weekend but my footings are a muddy brown moat, my bag of cement burst and I’ve got a rat in the shed. 
 

The flooding has shown where my amateur concrete finishing was not great and there are high and low areas to work with. 

Link to comment
Share on other sites

Below ground I would go 4:1 with nothing else - you won’t need it. Just make sure your DPM goes up and over the blocks when you do that. 
 

Laying blocks, get a straight bit of timber and see how much out of level corner to corner round the foundations you are, and see what the  gaps are you’re making up. Much more than 30mm won’t muck up so you’ll need to cut blocks down to the “highest” point if that makes sense ..??

 

20 blocks from 20kg of mortar is pushing it - it’s based on a 10mm bed and perps, so you’ll probably end up needing 50kg or so. 

Link to comment
Share on other sites

1 hour ago, PeterW said:

The only reason it’s making it easier is that it works as a plasticiser - any admix does that. 

 

I'm simply saying to use an admix, not necessarily that one though it's just cheap and works. 

Link to comment
Share on other sites

12 hours ago, PeterW said:

Below ground I would go 4:1 with nothing else - you won’t need it. Just make sure your DPM goes up and over the blocks when you do that. 
 

Laying blocks, get a straight bit of timber and see how much out of level corner to corner round the foundations you are, and see what the  gaps are you’re making up. Much more than 30mm won’t muck up so you’ll need to cut blocks down to the “highest” point if that makes sense ..??

 

20 blocks from 20kg of mortar is pushing it - it’s based on a 10mm bed and perps, so you’ll probably end up needing 50kg or so. 

It’s p*ssed down today so the whole thing is under inches of muddy water now ?

 

I think it’s within 30mm. I did go round trying to level it when it was poured but I ended up with more converter than the level of my markers. hoping it’s not more than +/-10mm.  Noted the high corners so planning on starting from there. 
 

Was going to use 4:1 from the research I’d done. Got 1 Cement and 4 sand. Just that the cement bag opened and spat out a load of cement dust when I put it in the barrow to wheel it down the garden. Should still have more than enough, looking at nearly 100kgs when mixed up? 
 

Assume the concrete will need to be relatively clean and dry to lay on, no ‘primer’ or anything on it before putting the mortar down?

Edited by daiking
Link to comment
Share on other sites

Weather is better so digging out the base whilst I pluck up the courage to mark out the wall with some string.

 

just how clean does the top of the footing need to be to start laying blocks on it?

1BCF62D7-8C2B-4FBC-A22B-062B39D09F3B.jpeg

AC0F3C86-49FC-4B37-B091-07045FC16D83.jpeg

Link to comment
Share on other sites

41 minutes ago, PeterW said:

Quick brush and crack on. 


steady on, these things take time.

 

I didn’t think I’d get the ground level as I was digging out but tramping round on it seemed to do the job. Still masses of roots in the ground. Hadn’t thought about a ground fabric/dpm under the EPS but might put something in.

 

You said just blind it with the thin EPS. No sand no hard core. Would you put something under it?

 

obvs the main DPM will be above the EPS with the concrete poured on top (like my house was)

Link to comment
Share on other sites

9 minutes ago, PeterW said:

Hardcore first then 25mm EPS. 


where?

 

I’ve got a hole down to the concrete footing,  225mm deep and planning to put 125mm of EPS and 100mm concrete into it. ?

Edited by daiking
Link to comment
Share on other sites

7 hours ago, PeterW said:

Need to take some more out and get a hardcore base in or it will settle. 

Yay, more digging.

 

This will expose most of the footings. It’s just over 12 sq m so approx 3bags / 2.5t of mot1 will give me around 100mm compacted sub base to the top of the footings

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...