How much plasticiser do I mix with?

The gauging water should be reduced accordingly to meet the required consistency. Add Thompson's Mortar Plasticiser to a rate: 150ml- 500ml per 50kg of cement, depending upon degree of plasticising required, or 2.5 lire per 200 litre drum of water. (The coarser the sand the greater addition rate required).

Can you use too much plasticiser?

They can also help prevent mortar shrinkage, which if it occurs, does not only look unsightly in mortar joints but also can allow water ingress. Excessive use of plasticisers can have an adverse effect on the mortar.

Do I need to add plasticiser to mortar?

Add plasticisers and other additives to the mortar mix to improve workability, but only if needed. Use only products specifically designed as a mortar additive. Use pre-mixed or factory-made mortar to ensure consistency throughout.

Do I need to add plasticiser?

Some people think plasticiser makes it much easier to work with the mortar, while some of them think it doesn't make any difference at all and it's just an optional thing in a mortar. Plasticiser isn't necessary to make mortar but it helps to create a smoother and creamier mixture without adding too much water.

Can washing up liquid be used as a plasticiser?

Basic washing up liquid acts as a plasticiser, but reduces the final set strength of the mortar. Many washing up liquids also contain soluble salts, which cause temporary efflorescence and are hygroscopic.

Mixing sand and cement mortar using a plasticiser admix

How do you make mortar stick better?

Why is my mortar drying too quickly?

If left under the hot summer sun, thin set mortar will set up too fast – as if you had mixed it with warm water. Direct sunlight on hot, dry days can cause mortar to lose its moisture to the atmosphere. This weakens the mortar and might not allow it to hold up over time.

What is the best mix for repointing?

A typical mortar mix for Repointing purposes, for use in an area subject to normal weather conditions, would comprise 1 part Portland Cement, 1 part Lime and 5½ parts Sand.

What does plasticiser do to cement?

Plasticizers are also often added to concrete formulations to make them more workable and fluid for pouring, thus allowing the water contents to be reduced.

Does plasticizer weaken concrete?

Now and again, plasticizers are utilized to diminish the concrete substance and warmth of hydration in mass cement.

Do I need to add plasticiser to concrete?

You use plasticiser when you need to improve the workability of concrete. Concrete's workability improves as you add increasing amounts of water. Increasing the amount of water in the mix beyond the optimum leads to weaker concrete.

What is the ratio of sand to cement?

What Is the Correct Ratio of Sand to Cement for Masonry? For general purposes, mix 6 parts sand to 1 part cement.

What depth should repointing be?

As a general rule, the pointing to be repaired must be dug out to a minimum depth of about two-and-a-half times its thickness, in other words ¾ inch to one inch for regular 3/8-inch pointing. You need to dig at least ¾ inch deep for thinner pointing.

Does adding more cement make mortar stronger?

To make the concrete stronger, add more cement or less sand. The closer you bring the ratio to an even one-to-one of sand to cement, the stronger the rating becomes.

What is the strongest mortar mix?

Type M mortar is the strongest of the four, and has a compressive strength of 2500 PSI. Type M mortar should be used when the structure has to withstand high gravity and/or lateral loads. Type M mortar is also a good choice for hard stone projects where the compressive strength of the stone is greater than 2500 PSI.

Why does my mortar not stick?

Why Won't My Mortar Stick? Most of the time this is a result of an incorrect ratio between cement and sand – if you have too much of the latter and not enough of the former, the adhesive effectiveness will be greatly reduced.

Why is my mortar crumbly?

Crumbling or failing mortar can be caused by a number of reasons: Failing mortar can usually be attributed to a lack of carbonation of the lime within the mortar meaning that the mortar will have little if any, strength.

How wet should mortar be?

Add just enough water to achieve the right consistency, starting with about — gallons for a cubic foot of mix. Mortar that is too wet will run out between the joints. If it is too dry, the bond will be weak. Mound the mix and form a depression in the center.

Can you over mix mortar?

The mortar should be mixed a minimum of 3 minutes and a maximum of 5 minutes after the last water has been added to the mix. The standard states that overmixing can change the mortar's air content.

How thick should mortar mix be?

The mortar should be fairly thick, like thick peanut butter. The thickness and consistency of the initial mix should be the same consistency of the final mix. Slaking is necessary! Do not add more water or mortar mix after the mortar slakes.

Can I put mortar on top of mortar?

Applying fresh mortar on top of old mortar that is loose or falling out will do little or no good; enough of the old mortar must be removed to make room for a layer of new mortar that is at least half an inch thick, and even then it is important to make sure that what is left of the old mortar is still solid and ...