How Long Does Mortar Take To Dry (And Why)?

Exact Answer: 36 Hours

Mortar is a blend of sand, cement, and water. It’s used to make bricks stick together. Mortar dries out by absorbing water from the air over time, and it takes about three days for the mortar to dry enough for use on brick walls. Once the mortar has dried, one should seal it with an exterior sealant. 

Mortar is an adhesive that binds together the sand and other materials to create a strong, durable material. One can use it in construction for making brick, stone, or concrete walls. The mortar needs time to dry before it hardens enough to use outside or inside the home. 

How Long Does Mortar Take To Dry?

Mortar takes about 36 hours of drying time outdoors and at least 7 days indoors. A good rule of thumb is that once the mortar becomes too thick to stir without using force, it’s considered properly set.

Mortar is an adhesive that binds stones or bricks together in brick form, and it is not the same thing as cement, though they are both used in masonry construction. However, they react differently when exposed to water because mortar absorbs moisture while cement reacts. 

The drying time of mortar depends on several factors, including the mix proportions and whether it was sprinkled with sand before installation or just plastered over without sand added in between each layer of jointing material. 

The amount of water exposure also affects how quickly the remaining wet mix inside dries out. There’s no way for them to dry out if they’re constantly wetted by rain or dew.

This is why mortar may take 36 hours to dry, depending on humidity, color, the thickness of mortar application, or whether it is water-reduced.

1) Drying time depends on humidity 

2) Drying time differs due to color 

3) Thickness of mortar application 

4) Water reduction can speed up or slow down the drying process

Properly mixed mortar should be able to dry in a day without the need for extra drying time. Even then, when one doesn’t follow mixing and or curing instructions correctly, there is no guarantee that one can set it up overnight. In both these cases, one should give the mortar at least 36 days before applying more humidity on it again.

Why Would Drying Mortar Take So Long?

For a seal to take place, the mortar needs to be set for at least 36 hours. In other words, it needs time for water from among other sources to evaporate from the dry mix and will remain sticky until then. 

Any less time than that, and a secondary sealer or steps is ideal for protecting whatever is sealed.

Ultimately, one of the reasons drying mortar takes so long is its simplicity arising from not undergoing chemical reactions during production, which leads to faster processes like air-drying, as seen with certain types of brick used as insulation materials. 

These factors also account for historically high durability rates and sturdiness associated with various buildings constructed using mortared stone walls throughout history, including castles.

The drying time of mortar depends on its composition. People confuse the characteristics of mortar and cement, but these are two different components of a paving mixture.

The drying rate also varies depending on the application of any air-entraining additive that might be added and on temperature and humidity. 

Mortar is applied at one thickness to direct contact with sub-base material without joints between units made from blocks or bricks to form a solid surface. 

It takes much longer for this surface to dry because it is subjected indirectly to wind or sun rays that would otherwise cause evaporation-driven convection currents in a more porous surface layer such as a brick paver flooring system.

Conclusion

To complete the mortar work properly, a mason worker needs to take care of a few things. Firstly, it is better to wet the bricks before putting the mortar on, and this way, the mortar can set slowly and absorb the moisture of bricks. 

It is also a best practice to spray on the mortar intermittently by using a hose.

Ensure to keep it covered when there is no work to keep the moisture in. This will aid the mortar in establishing a more solid connection between bricks and stone, allowing it to be as long-lasting as possible. If the mortar is not wet for the correct amount of time, the connections will weaken, reducing the building’s lifespan.

References

1. https://www.sciencedirect.com/science/article/abs/pii/S1359836803000520 
2. https://www.sciencedirect.com/science/article/abs/pii/S0008884605001055