Hydrated and Hydraulic Lime Renders, without cement

[nod]

28 minutes ago, jayc89 said:

I direct mix of hydrated lime and sand won’t set, no. It’s often used as a practice mortar for that reason.

 

But it can be made into a putty which will 

 

The putty lime is a skim coat Use on All interiors Pre ear It’s like spreading cream and drys rather than sets 

So can be left in a mixing box and knocked up when needed 

 

[SteamyTea]

2 minutes ago, nod said:

If you put mesh on you will never get any issues 

We guarantee all our renders for five years No quibble 

So we have to be belt and braces

I wonder if failed render is often a consequence of poor preparation.

It is easy to make a job fail, some workers seem to take pride in it to prove a point.

When I used to test bonding of dissimilar materials, I tried to include some known faults, the idea being that not every surface will be perfectly prepped.

That little ply to plastic test I did for @joe90 is an example. I should have sanded and cleaned both surfaces, but I just wiped the mildew off with my fingers and held the ply sample in place for 5 minutes.

 

 

[joe90]

34 minutes ago, nod said:

If you put mesh on you will never get any issues 

We guarantee all our renders for five years No quibble 

So we have to be belt and braces 

Shame you didn’t do @ProDave,s rendering 🤷‍♂️, in the shed of the house I just bought is a roll of fibreglass mesh, Polish (by the look of it) rather than chuck it anyone can have it fir the cost of the postage!

 

[ToughButterCup]

1 hour ago, nod said:

...

NO you don’t seal But you will need to mesh 

.....

 

Just in case some readers aren't sure what 'meshing' is, here's a photo in this case applied to an ICF.

The mistake I made initially was to try and apply the mesh when the first coat of render was already too dry, and the other was trying to apply it to a too first thin coat. Oh - and the weather was way too hot, and I didn't pre-wet the wall enough. Anyway .....

 

 

 

[SteamyTea]

It would be great to do some practical experiments on different rendering materials and techniques.

Round round off my working life a treat as I started off in a company that made material testing machines.

[jfb]

For OP - if going for hydraulic lime it is crucial to wet the wall properly first. In hot weather that means soaking the wall with a hose, get the mix on and probably wet the wall again prior to laying on. You will be amazed how quickly the wall will dry out after being soaked.

[jayc89]

2 hours ago, jfb said:

For OP - if going for hydraulic lime it is crucial to wet the wall properly first. In hot weather that means soaking the wall with a hose, get the mix on and probably wet the wall again prior to laying on. You will be amazed how quickly the wall will dry out after being soaked.

It’s a bastard for cracking too, so it needs to be allowed to dry slowly. When I plastered a room using NHL I damped it down a couple of times a day for the first week too. 

[larry]

11 hours ago, joe90 said:

Shame you didn’t do @ProDave,s rendering 🤷‍♂️, in the shed of the house I just bought is a roll of fibreglass mesh, Polish (by the look of it) rather than chuck it anyone can have it fir the cost of the postage!

 

I'll PM you! 

[larry]

11 hours ago, SteamyTea said:

It would be great to do some practical experiments on different rendering materials and techniques.

Round round off my working life a treat as I started off in a company that made material testing machines.

Just to say, we are only doing the front of our house... I'd be very happy to donate the rear for your laboratory!!!! 😅

[SteamyTea]

28 minutes ago, larry said:

Just to say, we are only doing the front of our house... I'd be very happy to donate the rear for your laboratory!!!! 😅

I just need the 'pudding'.  Not a house, that is not a good way to test materials.

[larry]

OK - thank you all for your comments. Just to come full circle. 

 

Had a good chat with the renderer yesterday. He was very reasonable about it all, and was happy to switch to using hydraulic lime. 

 

Scaffolding is now up and this evening I've given it all a good spray as suggested here. The heavens have now also opened so I daresay that should help. 

I've got a telescopic lance attachment now for my hose (feel like I've made it in the world now) so should also make things easier for keeping it damp over the next few days. 

 

We'll be using mesh - I think this was his plan anyway though just in case not I've got half a roll left from some upstairs DIY plastering and as a result of this thread one more roll on the way. 

 

Once again thank you to all who have provided advice here,  feeling much more positive about it now. Will upload a pic with some progress. 

[nod]

On 17/06/2023 at 10:50, SteamyTea said:

I wonder if failed render is often a consequence of poor preparation.

It is easy to make a job fail, some workers seem to take pride in it to prove a point.

When I used to test bonding of dissimilar materials, I tried to include some known faults, the idea being that not every surface will be perfectly prepped.

That little ply to plastic test I did for @joe90 is an example. I should have sanded and cleaned both surfaces, but I just wiped the mildew off with my fingers and held the ply sample in place for 5 minutes.

 

 

You make a good point 

We had a self build to render in sand and cement  (300 m2)

I told him I would have to put it For a couple of weeks due to the heat 

We are still using the through coloured renders as we can add an accelerator 

But sand and cement is no good in hot sunshine 

I’ve been past today and half of it has been done 

Would two weeks really make that much difference 

Hope he doesn’t ask me to re do it after winter 😂