How to repair cement roof tile pointing and bedding

[Thirko]

Cracked pointing?loose cement bedding between tiles that has slippedCraked pointing cement.

Following a recent discovery of a water stained ceiling I have found what I think is the problem - cracked and leakimg pointing and bedding for our cement roof tiles. Given that roofers and roofing plumbers are in very short supply I need to do some interim repairs until we can get a full inspection and repair done. How do I approach this and what products and tutorials are available. The house is single storey and the location is quite easy to access on the corner of the house

[Prawns · Accepted solution]

I had a go at repointing some of my roof - just dont rush it and it should look fine. I did mine with a pointing trowel and some dunlop pointing from bunnings which can flex slightly apparently. I just used a flatblade screwdriver to knock old suspect pointing off and used a wire brush to clean first.

[Jason]

@Thirko, 

Welcome to the Bunnings Workshop community and thanks for joining in the discussion. 

Great to see you receive such a prompt and encouraging reply from @Prawns. The ever-helpful @MitchellMc will also be keen to give you some pointers when he is back on the site on Friday. Let us know if you have any more specific questions in the meantime. 

Please don't hesitate to post anytime you have something to share with the community or need a hand with a project around the house and garden. We're here to help.

Jason

[redracer01]

Hello @Thirko 

I agree with @Prawns  recommendation. Please make sure that you are safe and that you are accessing your location in a safe manner to avoid accidents. Using a flat head screw driver to dislodge old, cracking and damaged pointing is perfect. I then suggest using a steel brush to remove any loose debris and expose the fresh side of the terracotta tile. If the tile is cracked or needs repair you can either effect a repair while you are up there or replace with a new tile either method will work. I suggest checking the whole roof to maximize your time up there and see if there are any other points that need replacing or repair. 

IMPORTANT : Look closely at the way the old pointing is placed in. Notice that there are tiny holes along the pointing. These are known as weep holes and allows the water to drain out as it gathers on the tile. If you do not put weep holes in the proper areas you will do more damage as water will now get trapped under the tile. Observe closely before attempting repair! Look closely where the weep holes are! If you accidentally block one you can still poke the pointing while it is still soft with a thick galv wire or a wire from an old wire clothes hanger. The hole does not need to be very big but it does need to be deep enough to allow water to drain out. Observe closely as you take it apart and place the weep holes in the same area when you put in the fresh pointing. There are dozens of videos mentioning this so please be aware.

Once you've mapped out your repair areas use pointing tool and pointing compound and proceed to repair. There are videos that show how to apply the compound. Best to do it when you know that there will be a few days of sunshine. Make sure to follow the instructions on the back of the can and use PPE as recommended when using this compound. Take care and stay safe.

Cheers,

Red

This is to repair cracked tiles.

[MitchellMc]

I'm glad to see you've already received some helpful advice @Thirko.

@redracer01 has given a thorough explanation of the process, and I would only re-enforce that if any loose material is found, you need to remove it, clean and fill the gap. Filling over a loose piece of mortar will probably not work well. It is better to repoint an area than repair thin cracks by patching over it. If the pointing is applied too thinly, then it will crack again. For the thin cracks in your images, as @Prawns has suggested, scrape them out well and enlarge them if possible before pushing your pointing into them with a trowel.

I'd suggest having a look at a few videos online about how to repair pointing. If you have any questions or get stuck with your repair, please let us know.

Mitchell

[Thirko]

Many thanks, appreciate all of the advice, hinst and tips. It will make the job a lot easier. I suspect given the paucity in roofers and roof plumbers at the moment I will need to do a more complete job than just an interim repair. The advice, products and tools to use will make it easier to do a proper job. I'd prefer to do it only once, properly, the first time.

Might post some 'after' pics.

regards

Peter T

[Thirko]

Thanks very much for advice

[Thirko]

Wow, thanks so much for the comprehensive advice, really appreciate it. This will make things so much easier. I'm feeling more confident about doing repair job now.

regards

Peter T