A cement mortar is known as roof bedding. Its job is to keep a lash on the roof tiles. Bear in mind that as time will pass, the bedding will gradually 
wear out. Once the tiles start to get detached, it is time for re-bedding.
Bedding is important because without it the roof might start splitting as the tiles have a high chance of getting loose and falling out. Unfastened roof tiles are dangerous for the people living in the house as it might fall on you, your loved ones and on your guests when you/they are leaving/entering the house.
Rain might cause leakages in your roof due to them being shabby and spoilt. If you do not pay attention to them, it might result in other kinds of problems as well (read: ceiling issues). It is your job to examine your roof at least once every month so that it literally doesn’t fall on your head.
The good news is that roof verges can be repaired and you don’t need outside help for that if you follow the listed instructions.
in this article
Get Hold of the Required Materials
First of all scrutinize over the roof from top to bottom and then get hold of the necessary things to repair it. It is not much expensive if you can manage to get the tools on rent. All you need to buy is cement and tiles.
Wipe All Dirt Away From The Roof Verge
Before starting work, ensure that you have adequate protection. Also, see to it that the ladder is tightly placed against the wall. Now, take a hard brush and wipe clean all the debris. Next, make use of a cold chisel to ward off the spoilt mortar. Take out the roofing material which is no longer in its place.
Make The Surface Ready
Get a soft brush to clean the debris and remove all the dirt that has gathered there due to cutting and shaping it with a chisel. Acquire dirt-free water and dampen the surface with a brushes’ help.
Blend the Mortar
Take three big chunk of beach sand and blend it with one portion of cement. Make sure that this is done on a wheel barrow. Now, add a large volume of water to it and blend it inside out. Add some more water to mix it well. Keep on repeating this process until the mortar becomes smooth and even.
Use The Mortar
Put the mortar in an old tub and make use of a trowel to put it on the very same region where the old mortar was once put.
Examine the Roof Verge
Once you are done with the repairing, leave it to dry by itself. Examine the applying of mortal once again and be extra alert about splits and 
inconsistencies on the exteriors. If the mortar has been applied correctly, eventually its colour will turn gray after it has been fully dried.
In case the condition of your mortar roof verge is not good, you can consider dry verge system as an alternative. Dry verges are created from moulded UPVC. If you are wondering about whether they will match your present tiles, worry not because they are obtainable in multiple colours and styles.
This means that there will be at least that one colour/style which would complement your tiles. But, there is a catch – if you want to install dry verges, you need outside help as it is not a thing for amateurs. Dry verges can be effective if you get them installed properly because they are known to make a visually unpleasant roof look good.
Keep the following factors in mind for roofing mortar:
- Ratio of cement plays a crucial role here. The positive results are largely dependent on the amount of cement you are using. So, don’t be a miser with it in case you need a lot of work done up in the roof.
- Also, keep in mind the climate around you. In winter – if it is very cold or freezing, then it can affect the re-bedding. Ironically, if the weather is too good, the work might get affected for that too.
- Most people just pay heed to the quality of cement. But, the condition of sand is equally important. If you the results to be effective and long-lasting make sure that the sand quality is good.
- Check the roughness of the surface thoroughly. Because later you don’t want your work to become a failure because of that. For best results, do the inspection when the roof is in proper condition.
- The underlying substance that the mortar wills tick to is very important. I fits dry, you need to do your job differently than what you would do for when it is glossy or sandy.
- You definitely need frost resistance. Thankfully, there are lots of adding ingredients which can be sued in the cement to make the mortar better. Keep in mind that the most commonly used additive is a plasticiser.
- Cement which has the ability to quickly dry up the mortar is the best. If you are pressed for time or the weather is not being your best friend, then this factor shouldn’t be overlooked.
In the UK, you will find rain and showers frequently. If you are working with mortar on a rainy day, chances of your job being unsuccessful is high. But, on days when there is little rain or just drizzle, you can easily work with sand and cement, provided there is not a lot to work on. Cement which dries superfast can be your saviour in this kind of weather.
As far as the quality of sand is concerned, as previously mentioned, it should be in proper condition. So, if you are on a budget, then by all means go for the usual building sand but bear in mind that soft building sand might not always work in your favour. If it does not, hen go for concrete sand as it is able to fill the bigger gaps efficiently.