advice on to seal or not? durox blocks b4 rendering??

[rattyboomboom]

do we need to seal ie pva,durox blocks b4 we render or just spray down walls before...they suck up water so quick i am wondering whether it will bond properly??
any advice please

 

[tawelfryn]

spray them down. I would dot and dab though, not render.

 

[rattyboomboom]

these are external walls....the internals were dry lined..all ok..but the exterier is 95% ok so far but has blown (not fallen off but hollow and cracked) in a couple of places. we have some v big walls to do so need to get it spot on..

 

[noseall]

i for one would never use durox, celcon or tarmac toplite blocks on an external build, you just can't get a good enough key for rendering.

the denser rougher granular ash type should have been used or even 7 nuton concrete.
these give a far superior key.

are durox suitable for external use? what did b.c. say?

 

[tawelfryn]

durox for external? never seen it, and I have been a brickie for 18 years unless theres a newer type I have not seen especially made for external

 

[rattyboomboom]

oh s t this is really not the answers i expected...............b.c were ok with it but yes it now seems a bad move.......if i were too spray down 1st,then render (scratch then top) then seal the outside with a sealer??? do you think like i that this would make the water go into the block more than drying out??? thus hopefully making the render take better???HELP THERE MUST BE SOMEONE WHO HAS DONE THIS?

 

[legs-akimbo]

Ratty. Hose down the walls firstly then apply a scratch coat with plenty of waterproofer in it. Make sure the mix has been well turned in the mixer and is a nice wet consistancy. When the scratch has cured over the next two days you can then give a light spray with water and render with your floating coat, the high suction will have been deadened by the waterproofed scratch. Ask at your builders merchants for a product called medusa as your waterproofer, supposedly very good in this type of situation. Have not used it myself as I can not get it where I live.

 

[legs-akimbo]

And do not under any circumstances pva external block work prior to rendering...NEVER NEVER NEVER!!!!

 

[noseall]

8)

good to see ya legs.

like a knight in shining armour.

 

[legs-akimbo]

Wotcha noseall, hows the spreading arm?

 

[jbonding]

And do not under any circumstances pva external block work prior to rendering...NEVER NEVER NEVER!!!!

as a key i would agree but to kill any suction and dust its ideal, also mixed with cement and some sand to a slurry its also sound.


so they let you out on a tag hey legs.

 

[noseall]

the arm parts ok.

me shoulder gets a bit stiff, an its effecting me golf.

 

[legs-akimbo]

Am on the run j.b. they will never take me alive!!!!

Noseall how the heck do you find the time to play golf, keep promising myself that I will give it a bash some time but never seem to get around to it, some fine courses near where I live too

 

[noseall]

work very hard mon-sat and the wife lets me play sat a'noon.

have played;
athenry,
east clare,
nenagh,
portumna,
tullamore,
ballinasloe,
and glasson.

great country ireland.

 

[legs-akimbo]

Is that Ballinasloe in Galway? Not too far from me (about an hour) Nice little town!
Prefer to go out and get twisted drunk than hit prickly little balls with metal sticks myself.