How to Make, Mix and Use Mortar for Repointing

Making Mortar With Sand and Cement

This is a guide on how to mix sand and cement to make mortar. This knowledge can be very useful for various DIY projects around the house, including roofing work like bedding or pointing of ridge tiles, replacing bricks and pointing stone or brickwork.

Although it's not particularly difficult to do, there are a couple of things to know. I've been making and using mortar for years, so read on to find out how to do it right!

What Kind of Sand Should You Use?

If you want the dry mortar to be:

• A middle tone: Use builder's sand
• Dark: Use red sand
• Light: Use yellow sand

I mostly use red sand because it's darker and doesn't stand out so much. So, unless you have a specific reason to use yellow sand to match what you may already have on there, I'd recommend red.

How to Mix the Sand and Cement

If you're mixing by hand, then you'll need either a bucket or a board, depending on how much mortar you need. If you only need a small amount of mortar, then it can be alright to do it in a bucket.

The easiest way is to put the sand and cement into the bucket or board with a trowel. You can match one heaped trowel worth of cement to three trowels worth of sand. Then repeat with more cement and more sand as you fill the bucket. If you do it this way, then it makes mixing it up easier, as it's already getting mixed up as you put it in the bucket or board.

Don't fill the bucket more than just over halfway, however, or it will make it too difficult to mix it all up correctly.

How to Mix in Water and Plasticiser

Once you've thoroughly mixed up the sand and cement, it's time to start slowly adding the water and some plasticiser. The plasticiser is important to make the mortar easier to work with, and it also stops the mortar from cracking when it dries.

You want to keep mixing the mortar as you slowly add the water until you get the right consistency. The easiest way to check if the consistency is right is to use the top of a clean trowel to lift the mortar from the bucket, then hold the trowel on its side. You want the mortar to stick to the trowel a bit but not stick so completely that it slides off very slowly. If it's too dry, then it won't point properly. And if it's too wet, then it will slide out.

You also need to check the mortar by smoothing it off in the bucket with the trowel. It should be a nice, smooth finish with a small number of foam bubbles visible. If you can see any cracking or a sandy texture, then add more cement. If it gets too sloppy, then add a bit more sand. If you don't have enough cement, then the mortar will crumble when it dries.

If you stick to the 3:1 ratio method, you should be fine. But now and again, you'll still need to add a touch more sand or cement. Ideally, you should use the same proportion of sand and cement for all of the pointing you're doing so that it will all dry the same colour. But a trowel's worth of sand or cement more per bucket here or there won't make a difference.

Tips for Mixing on a Board or in a Wheelbarrow

If you're mixing on a board or in a wheelbarrow, the same method applies on a larger scale. Mix dry, then add the water. If using a barrow, you can fit two bags of sand and two-thirds of a bag of cement in there without overfilling. You still want to use the plasticiser, and you will still need the trowel to check the consistency after you've mixed everything together. It's also a good idea to put a tarpaulin down underneath your mixing station to contain any splashes.

Tips for Mixing in a Cement Mixer

If you're mixing in a cement mixer for a larger job, then the easiest way to add the water is to spray it in with a hose. Make sure that you add the water slowly and let the mixer do the hard work. If you put too much water in too quickly, it will start splashing out everywhere. And it can fly quite a distance, so be careful! It's also a good idea to use goggles when you're using a mixer, as it can be pretty painful if some does happen to splash into your eye.

The most important thing to remember with a mixer is to not let the mortar dry in there. After emptying it out, put some water and loose half bricks or pebbles in there, let it swill around, and empty it out again. Then hose it out. If you do this while the mix has just been freshly made, it's a lot easier to clean out than if you let it dry.

How to Repoint Properly With Mortar

In order to repoint properly, you need to get as much of the old mortar out as possible. You can use a grinder and then a hand brush to clean the old material out until there is no loose mortar left. If you just go on top of old stuff that's loose, then the new mortar you put in will just come out again. So if you're going to do it, then do it right!

Remove the Old Ridge Tiles

Similarly, if you're repointing or rebedding ridge tiles, then it's normally worth taking off the old ones and cleaning off all the old mortar. You can use either a brush or sometimes a hammer and bolster (a mortar chisel), depending on how stiff the old mortar is. (Although if you don't crack them, you can usually reuse ridge tiles.)

If you just go over the top of the old mortar, it's a lot quicker, but what you put on will crack and fall off. What most roofers do is put the mortar line down, then use broken pieces of tile between the ridge tiles—mixed in with the mortar—to add some strength. This stops it from dropping down between the ridge tiles and allows you to build it up effectively.

Add the Mortar in Stages

When you start pointing, it can sometimes be beneficial to add the mortar in stages, depending on how and what you're pointing. If you have large gaps to fill, then put a layer of mortar in rough and leave it to dry for a few hours. You can then go back and point it up with a bit more to finish.

If it is a large gap and you try to do it all in one go, it can look great when you've first done it, but then slowly slide out and leave a gap at the top. You don't want this! If you're just doing brickwork or small gaps, though, then you don't need to worry and can usually do it in one go.

Keep Your Trowel Clean

Make sure that you keep your trowel clean. This will make the whole process easier. As you point, you will need to repeatedly clean the trowel off on the side of the bucket or something similar to keep it clean and clear. And, of course, when you're done, give it a good scrub to keep it ready for next time.

This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.

© 2012 Rain Defence

Comments

peterlee on October 22, 2017:

very good article

J keely on October 30, 2016:

Hi, great info, but can you tell me the mix and what to use for lime mortar for a very old chimney we need to re point.

Thank you

Danielle from Toronto on September 09, 2016:

I really like this post. It's not often you find helpful tips on this sort of work.

Clive Trott on July 24, 2016:

Looking at other articles, most suggest a 3-1 mix too strong and suggest 5-1, and the best mix is using lime

Rain Defence (author) from UK on August 08, 2015:

You're best to use red sand in my opinion. The mix is then dark. If you use yellow sand the mix ends up pretty light in my opinion and isn't as appealing.

Randall Cornell on July 31, 2015:

Repointing the brick where mortar has fallen out, worn away, or is just too deep. This can be labor intensive depending on the age and condition of a brick wall, but well worth it. Your hub is very informative!

mick on March 12, 2015:

I want just a plain grey mortar finish, best to use a yellow sand?

Rain Defence (author) from UK on September 01, 2014:

I'd just buy one bag for that. Cement is extremely cheap by the way so even if you bought 2 in case you messed up the mix it would cost you peanuts. Good luck!

zia on August 18, 2014:

how much cement used in 1 Sqm or Sqft pointing work of boundary wall?

Rain Defence (author) from UK on July 18, 2014:

Thanks!

The Councillor on July 17, 2014:

really ueful, cheers

Rain Defence (author) from UK on June 30, 2014:

You're welcome! Thanks for your comment.

Dave S on June 30, 2014:

Thank you very straight forward giving the information as it is needed!

Rain Defence (author) from UK on May 13, 2014:

I always use a 1 to 3 mix. Just don't forget the plasticiser! The sand colour will affect the finished mortar colour.

ashy on April 10, 2014:

hello, i want to use white mortar to repoint my walls of my house. do i use 1 part white cement to 3 parts sand. is it ok to use silver sand with the white cement as i believe that silver sands keeps the cement white. cheers

Rain Defence (author) from UK on January 08, 2014:

Thanks for your comment, just keep an eye on the forecast, we are due some sun at some point (I hope!).

mikey on January 06, 2014:

HI thanks for the very straght forward instruction ,on how to mix the right mix quantity, and good tips on actually doing the pointing job , just waiting for good weather now,cheers,mikey.

Rain Defence (author) from UK on September 27, 2013:

You'll be fine, just take your time and don't forget the gloves!

kev on September 27, 2013:

Thanks a lot i have been dreading doing it but now not so much so

M/S Chrys. on July 25, 2013:

Just what I was looking for. Plain English and easy to follow. When I need help again I now know where to look . Many thanks.

Rain Defence (author) from UK on July 12, 2013:

Put some in. If its red, it's right!

Rain Defence (author) from UK on July 12, 2013:

I put a splash of plasticiser in. I don't measure it, but put in say 1/3rd of a cupful into a bucket for example.

Jack Frost123 on July 11, 2013:

just wondering, using the one part cement and 3 part sand method, how much oxide do i mix in to it?

jack frost on July 11, 2013:

using the one cement and 3 sand formula for re capping rooftiles. to make it red how much oxide do I use?

Zubair Ahmed on February 18, 2013:

Hi,

Very useful hub, something I really need to do this summer on my house. I noticed some of my exterior walls require repointing. Now I know how easy it can be i'll give it a try.

Thank you for sharing

Rain Defence (author) from UK on December 21, 2012:

It's true! If a jobs worth doing, it's worth doing well.

Masonry Mortar on December 20, 2012:

The durability of the wall is highly influenced by the quality of the mortar joints and interior cell grout. 

mikew on October 09, 2012:

Really useful page. Cheers for the info

furniturez from Washington on August 08, 2012:

Awesome stuff, I was looking around for something like this for a few weeks! Now it's time to get to work :)