Roof Mortar Crumbling

So what are the causes of crumbling mortar.

Roof mortar crumbling.

Chimneys are often positioned in exposed areas of the roof and crumbling can occur due to weathering even if other brickwork around your home is in good condition. How much cement in a roof mortar mix. Your builder is wrong to say its fine if the mortar is crumbling away. This is a beginners guide to pointing up.

The correct mix ratio is 3 parts sand to 1 part cement this is much stronger than bricklayers use 5 1 as the cement on the roof must withstand more driving rain than a typic. Great for brickwork chimneys or roof details like flashings. This is generally a straightforward thing to do. In most cases a crumbling.

The fact that it is very porous means that it can hold water. 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. This not only causes cracking but it can also cause crumbling as the mortar denigrates. The mix sounds ok at 4 1 if this is what he did use the problem is either the sand is to soft and maybe should have been sharper or i suspect he done it during the low temperatures we had and it has killed the mortar which i try to avoid or never used a wintermix frost proofer or covered his work up at the end of the day.

Crumbling or failing mortar can be caused by a number of reasons. The roof verge will need to be rebedded with mortar. The temperature change that comes with the seasons can also mean the swell and contracting of the mortar. Roof cement is primarily used to hold roof tiles hip tiles and ridge tiles securely in place it also keeps out rainwater.

This is a great concern and something that highlights the need for a better understanding about what it takes to create a long lasting and top quality mortar. 1 mix 3 parts sand to one cement.