Roof ridge mortar mix

[danielbb]

Seems to be a lot of differing opinions on what mix is best. eg building, sharp or plastering sand, dedicated plasticiser or fairy liquid. Anyway, taking all the info into consideration ive decided.

1 part sharp sand, 2 parts building sand, 1 part cement, proper plasticiser, dye and as little water as possible whilst retaining a decent mix.

Sound about right?

Also, Is there any dedicated mixs available off the shelf? I see some Flexi-point stuff but that is for the US market only? Any similar products here?

Thank you all.

 

[BethesdaSlate]

That mix sounds fine, though personally I wouldn't bother with dye.
Just make sure you keep the mix consistent and for best results dampen the ridges first if you can.

 

[Nige F]

Just had mine done - builder used mastercrete cement because it`s got plasticiser etc. in it no colourant used .Gauged with a bucket - not by the shovelfull - The guy is OK , I went to school with him in the 60`s and he`s been building since 1970 I just did the odd bit of rainwater goods round the new fascia

 

[hammerswinger]

Beware of light coloured cements like Mastercrete, depending on the sand used you could end up with very light mortar which stands out like a sore thumb on a roof.


Cheers

 

[Nige F]

Good point - but it looks OK with the lime mortar walls here - might not on another place

 

[danielbb]

Beware of light coloured cements like Mastercrete, depending on the sand used you could end up with very light mortar which stands out like a sore thumb on a roof.


Cheers

Indeed ive seen a few, very light grey, looks a mess.

 

[^woody^]

LOL, cement is cement and roofs get dirty quickly

Mastercrete is more marketing than anything significantly beneficial. You'll get different shades and consistency depending on whether the mix goes around the mixer 50 times or just gets turned over a few times with the shovel

Sand has more to do with the final colour

 

[danielbb]

Hence ill be using dye

 

[^woody^]

But dyes on roofs don't last 5 minutes

 

[hammerswinger]

LOL, cement is cement and roofs get dirty quickly

Mastercrete is more marketing than anything significantly beneficial. You'll get different shades and consistency depending on whether the mix goes around the mixer 50 times or just gets turned over a few times with the shovel

Sand has more to do with the final colour

Whilst I agree that roofs will weather down quickly and that the colour of the sand will play a big part in the finished colour of the mortar the cement should not be overlooked, not all cements are the same & some produce a much lighter finish than others.

I've just been through the "Cement is Cement" debate with the builders merchant who delivered Rugby Premium cement which has printed on the bag: "Lighter Colour ideal for a lighter finish in Mortars & Concretes", this produced a very light (whitish) mortar when mixed with Yellow sand, where as standard Blue Circle cement produced a much darker (Grayish) mortar with the same sand.

Cheers.

 

[^woody^]

Clearly if a cement is manufactured to be lighter and purposefully says so on the bag, then it will [should] do as it says.

But bog standard ordinary portland, whether its Rugby, Blue Circle, Quinn, Castle or whatever, or Mastercrete (which is basically just a bit finer ground) then its effect on final shade is not much

 

[hammerswinger]

Yes any ordinary portland cement should be roughly the same colour but not all are, Mastercrete in my experience produces a light mortar.

In a lot of cases it doesn't matter if the mortar is a shade lighter / darker,
but if you're trying to match a mortar the cement chosen could make a World of difference.


Cheers.

 

[datarebal]

"But bog standard ordinary portland, whether its Rugby, Blue Circle, Quinn, Castle or whatever, or Mastercrete (which is basically just a bit finer ground) then its effect on final shade is not much"

I'd say not true... it can make a big difference, try changeing makes half way through a job..