# Forum Home Renovation Roofing  repointing the corner roof tiles

## barned01

Hi guys, after requiring to remove the hip tiles that meet to an external corner to put up my pergola, iIwould like to re mortar the tiles down.
I used some cement and sand once before but it didn't last long, so before I do these ones, is there a special mix I am supposed to use? do I need to add lime or something.
It kind of looks like my whole roof needs redoing, but at the moment i am only worried about these two corners

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## atregent

I found this info in a brochure from CSR that may be helpful. I have also seem buckets of pre-mixed stuff at Bunnings, which may be handy for smaller jobs  *Bedding Mortar Mix*
Australian Standard 2050 Installation of roof tiles requires as a minimum..
Cement mortar for bedding (1:4) 1 cement, 4± 0.4 sand.
The use of other additives such as Lime, Fire clay is permitted at the following ratios:
»»Lime composition bedding mortar (1:1:6).. ..1 cement, 1± 0.25 lime, 6± 0.6 sand.
»»Fire clay when used, replaces an equal amount of sand therefore, if 1/2 a measure of fire clay is used the ratio would be (1: 0.5: 3.5) ...1 cement, 0.5± 0.005 fire clay, 3.5± 0.3.5 sand.
Fire clay is not a replacement for cement. The use of plasticizers and products that aerate mortar is not permitted as these products weaken the mortar.  *Pointing Mortar*
Cement mortar bonding shall not be used as the mechanical fixing method. It can be used however in conjunction with some other form of mechanical fixing.
»»Pointing mortar when used shall be 3-1 mix, 3 clean sharp sand, 1 cement, with oxides or pigments to suit.
»»Flexible, premixed pointing is available and in most cases is rated as a mechanical fixing. Check with the manufacturer for confirmation of status.  *Bedding and Pointing*
The pointing should be neatly trowelled, with an even finish throughout. Collar/cuffs should be pointed (if Flexible pointing is the mechanical fixing then it is mandatory to point collars/cuffs.)

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## Bloss

Nah - use one of the the flexible acrylic based pointing mixes such as Flexipoint. Any HW store or roof tiling place will have it and some landscaping places even - tubs of various sizes and range of colours.  :2thumbsup:

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## barned01

assuming i found the tub today (39 bucks at bunnings for what looks like it is a 15 litre odd container), i would be worried how much of this i would need.
the existing hip tiles had a generous amount of 'mortar' on them already,i would be afraid i might need 2 buckets per corner (and i have 2 corners)
is this the stuff you are talking about?
this makes doing an entire roof an entertainingly expensive proposition

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## crackerwoody

the flexible is for the pointing only, you need to go back to bunnings , get some adelaide brighton 'basic mortar', to replace the cement under the caps, while its wet , cut off any excess mortar, let it dry well, sweep up the debris, hose the dirt stains off with a broom then put a layer of the flexi over the top of this. go to soldertech ,lloyd st, st marys, ask for some shieldcoat roofbond, they have many colors, lot better stuff than bunnings sell

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## Bloss

> assuming i found the tub today (39 bucks at bunnings for what looks like it is a 15 litre odd container), i would be worried how much of this i would need.
> the existing hip tiles had a generous amount of 'mortar' on them already,i would be afraid i might need 2 buckets per corner (and i have 2 corners)
> is this the stuff you are talking about?
> this makes doing an entire roof an entertainingly expensive proposition

  You can get it cheaper than at Bunnings, but remember to this is for 'pointing' not bedding too (for which you use mortar) - you do not use all that much of it. In any case a ~$200 cost for 20 years or so of roof sealing doesn't seem much to me (but if you haven't got the cash it's hard to agree I know!).

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## barned01

'i see' said the blind man
use mortar first (as i did once before) but then use pointing compound to secure the tiles as opposed to just sinking the hip tiles into the mortar.
it all makes sense now, the hat goes on the head
although do i put a little bit of pointing compound on the lower tiles also or just straight mortar for them? 
i shall proceed gung ho into it tomorrow i shall try this soldertech place also, hoping they are open on saturday morning 
200 i have no problem with, my initial thought was that i was going to need copious amounts of buckets to fill the space also rather than just provide a skim coat, but now i understand (and now atregent's  full post makes sense to me as all steps are relevant)

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## autogenous

> assuming i found the tub today (39 bucks at bunnings for what looks like it is a 15 litre odd container), i would be worried how much of this i would need.

  You need to bed the tile capping tiles first with 4 sand, 1 cement with quite a stiff mix.
Tilers normally bed the hip capping with the a ladder 
Then you point a skin of coloured mortar or the flexi-joint product approximately 2-3mm thick over the top.

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## hohners

Thanks all for the helpful posts. 
A question on a related problem. The pointing on my roof is cracked. The tiles on the hip (the ridge) are still firmly attached but the cracks are significant at some points. 
Do I need to fill the cracks in with a mortar & sand mix (1:4) or can I just fill the cracks in with something like Flexi-point or Tilepoint? 
BTW - Tilepoint says it doesn't meet standards for mechanical fixing.

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## lukelegend

> Thanks all for the helpful posts. 
> A question on a related problem. The pointing on my roof is cracked. The tiles on the hip (the ridge) are still firmly attached but the cracks are significant at some points. 
> Do I need to fill the cracks in with a mortar & sand mix (1:4) or can I just fill the cracks in with something like Flexi-point or Tilepoint? 
> BTW - Tilepoint says it doesn't meet standards for mechanical fixing.

  I would like to know the above post also?? Do you need to remove the cracked pointing/fill first or can you just go over it with Flexipoint?

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## crackerwoody

if you can , get a pressure cleaner, even a small karcher or something, and blast the old capping clean, if you cant , use a wire brush. any hole or crack you can stick your finger in should be filled with mortar first, then left to dry overnight. then point, but remember , if you mess it up, it will cost more to have fixed by a pro than before you tried. good luck!

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## rrobor

30 years ago when the house was 5 years old the ridge caps on my roof came slack and in a gale used to rattle etc. I found the mortar was shot. What I did was pack the gaps between the tiles with plastic I used bubble wrap I then covered the lot over with mortar and bedded the capping tiles down and pointed the sides. That was 30 odd years ago, my neighbor has had his done 3 times I have never touched my ones. Sure the fillets on some have fallen off but that doesnt matter. But word of warning do not do this in valleys. In a valley there must be a track beyond the mortar for water to run down so if you fill most of the valley you will find that if it develops a crack between mortar and metal valley this acts as a capilliary and sucks water to the other side, it then runs down under the tiles till it hits an obstruction and that can cause a wet patch in the house.

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