30" cast dome design

[sergetania]

David, very sorry to hear about the health issues! Sounds really nasty! Glad to have you back and wish you the fastest recovery!

Sorry, I was not clear. Definitely doing a vcrete layer but want to skip a stucco layer(outer render) and just paint the vcrete with flashing sealant. Good or bad idea?

[david s]

Sorry, been out of action, in hospital for the last 4 weeks. A nasty staf bug got into my blood, attacked my aorta valve flicked off some bits to my brain causing minor eyesight problems and major back pain. Open heart surgery to replace valve and long term antibiotics to kill bug, hopefully going home next week. To answer your question, some folk have rendered against blanket successfully, but it is quite springy and not a good substrate to work against, resulting in inconsistent outer layer thickness. A layer of vermicrete over the blanket can restore a perfect hemisphere, evening out the lumpy blanket and giving you a nice firm substrate to work against.

[sergetania]

david s Thanks! Missed you - hope everything ok!?

David, not sure you have seen a discussion above. I am planning to waterproof with elastomeric flashing sealant
https://www.amazon.com/dp/B004SIB2JI..._iaExFbEW59BBB
over the vcrete layer (with breather) skipping the other render. Ok or bad idea? I may need to smooth out the area around facade but otherwise, why do I need to do stucco all over vcrete? Thanks!

[sergetania]

If you mean putting the flue in place first and then firing I think it could be ok - personally I also got the vermicrete layer on top of the blanket too before starting.

Yeah, I guess I would need a flue

[david s]

The outer arch looks nice. I’d attack the silicon with a stiff scrubbing brush then grout the tiles with a black grout.
most builders use a 10:1 vermicrete or perlcrete over the blanket to restore perfect hemisphere and to provide a firmer substrate to render onto for the final outer shell. I like to drive out excess water after vermicrete layer but before outer tendered shell.

[Mullster]

How does this look? I think the wire holds it down well enough.

Shall I start the curing fires or wait till the outer layer is in place? Thanks!

If you mean putting the flue in place first and then firing I think it could be ok - personally I also got the vermicrete layer on top of the blanket too before starting.

[sergetania]

How does this look? I think the wire holds it down well enough.

Shall I start the curing fires or wait till the outer layer is in place? Thanks!

[sergetania]

Done with the facade. Glued the tiles to the bottom of the form with silicone. I will need to figure out how to get the silicone of the tiles. I should have used something else. Do I love the look? I think it is decent and hopefully will get better when dry, clean of silicone and framed with the outer layer.

[sergetania]

If it's recommended applied over vcrete then by all means go with it and save yourself some work.

That's what I have been trying to find out. It should stick and waterproof. What else do I need? It would be nice if I could skip the stucco. Especially the brown coat! It just doesn't sound good

[Mongo]

George,

Is being porous the only reason why I need the stucco layers? In order to seal the vcrete? This product recommended by david s in one of his posts is 100% waterproof so it should do the job and no stucco is needed

https://www.amazon.com/gp/product/B0...29IE922V&psc=1

Is David around? Trying to figure this out. Thanks!

If it's recommended applied over vcrete then by all means go with it and save yourself some work.

[sergetania]

George,

Is being porous the only reason why I need the stucco layers? In order to seal the vcrete? This product recommended by david s in one of his posts is 100% waterproof so it should do the job and no stucco is needed

https://www.amazon.com/gp/product/B0...29IE922V&psc=1

Is David around? Trying to figure this out. Thanks!

[Mongo]

Mullster Thanks!
Yes, that's exactly what I was hoping for. A vcrete layer and then paint over with a waterproof coat. Do I need anything on top of the vcrete before waterproofing? Won't it work? I have no idea hence I have asked.

Vcrete is going to be pretty porous. I recommend stucco over your vcrete, then finish and seal your stucco. Note, no cement product is waterproof, however stucco is more water resistant than vcrete.

[sergetania]

Mullster Thanks!
Yes, that's exactly what I was hoping for. A vcrete layer and then paint over with a waterproof coat. Do I need anything on top of the vcrete before waterproofing? Won't it work? I have no idea hence I have asked.

[Robarb]

Yeh, scratch coat, then final coat. Some even put two thinner scratch layers on i believe

[Mullster]

sergetania great progress again. Just checking - are you suggesting simply sealing the vcrete layer? I’m no expert but I would have thought you need a render layer on top of the vcrete first?