Do I need plasticiser in mortar?

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.

Is mortar plasticiser necessary?

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.

What is plasticiser used for in mortar?

Thompson's Mortar Plasticiser is a surfactant based liquid admixture for modifying cement mortar used in brick laying and pointing mortar, back coats, renderings and blockwork. It is designed to improve plasticity without the addition of lime and increases resistance to freeze thaw cycles in the set mortar.

Do you need plasticiser for pointing?

The use of plasticiser in mortar is standard practice & not a special requirement of the Point Master.

Does plasticiser weaken mortar?

Excessive use of plasticisers can have an adverse effect on the mortar. Lime added to mortars is well known for giving them a soft, putty-like consistency which can make them easier to work and retard their setting.

Mixing sand and cement mortar using a plasticiser admix

Is Fairy liquid a good plasticiser?

Captain Leaky New Member. "Washing up liquid affects the long term structural integrity of mortar and should never be used as a substitute for plasticiser."

How do you make mortar stick better?

What is the correct 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 happens if you use too much plasticiser?

It puts to much air into the mix which makes it go like fluff. Once it's hard you end up with voids in the motar so it's not as strong as it should be. With voids then frost can get into it and it will crumble. I always used this type where you have the small bit at the top to measure it out.

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.

How much plasticiser do I mix with?

Squeeze the bottle until the liquid in the cup rises to the correct level, 8 – 12ml per 25kg of cement is recommended for most uses.

Can I add PVA to mortar?

PVA can be added to a cement mortar mix to give the mix a) slightly better waterproofing qualities and b) advanced adhesion to the surface it is applied to. Painting a coat of PVA on the surface before the cement mortar is applied can even further increase this adhesion.

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.

How do you keep mortar from sticking to a mixer?

Coat the mixer

Apply a thin coat of industrial grease on the outside of the mixer to prevent cement accumulating and hardening on the surface. You may also add a light coat of diesel to the drum's interior before mixing. This prevents the cement from sticking to its insides.

How does a plasticiser work?

Plasticizers do their job by acting as a kind of “lubricant” between segments of polymer chains. Without the plasticizer, those chains of molecules would sit on top of each other as rigidly as uncooked spaghetti in a box.

Does plasticizer weaken concrete?

Adding an excessive amount of plasticizer will result in excessive segregation of concrete and is not advisable. Depending on the particular chemical used, use of too much plasticizer may result in a retarding effect. Plasticizers are commonly manufactured from lignosulfonates, a by-product from the paper industry.

Can you use Fairy liquid in mortar?

Using fairy liquid can create bubbles and lead to voids in the mortar.

What's the best mortar mix?

The preferred mix ratio is 1-part lime, 1-part cement and 6 parts sand. Alongside the aforementioned materials you will of course need water. The sand in question should be either rendering sand or plastering sand. It's possible to purchase a ready-mix render or to make it from scratch.

Is plasticiser a Waterproofer?

Waterproofer and Plasticiser is a concentrated Waterproofer and Admixture combined for cement mixes to reduce water permeability and entrain air. It can be used in concrete, renders and mortar to reduce the passage of moisture and suction.

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.

How do I make a dry mix for pointing?

Use a dry-ish building sand, plastering sand or, if so desired, a Kiln Dried Jointing sand. Some installers like to use a coarser or sharp sand, but this can result in a rough-looking finish when used for dry grouting. A 3:1 ratio of sand and cement are mixed without the addition of ANY water. None.

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 long before mortar goes off?

Mortar typically will cure to 60% of its final compressive strength within the first 24 hours. It will then take about 28 days to reach its final cure strength. However the curing process does not always follow a universal timeline.

Is Lime a plasticiser?

Lime in mortars

Hydrated lime is used in modern cement based mortars mainly for its properties as a plasticiser.