Hairline cracks on plastered walls - worries

Hiya. I wouldn't worry to much it may just be shrinkage when the wall has driied, did you stabilise the wall prior to plastering. If the wall is hollow the plaster has no adhered well. If it sounds solid then just miss coat and fill with powder filler to any cracks

Hi Sara, there are a number of reasons the cracks could have appeared and this issue is common when plastering onto solid wall, (causes can be movement in Material behind the plaster, loss of moisture, plaster drying too quickly, and humidity levels) I would suggest at this stage, with them being hairline cracks it isn’t anything to worry about. They can be filled, sanded, repainted and then monitored, (always open the crack slightly when filling & repairing!) If large cracks start to appear they are more worrying and can be a result of the plasterers finish, such as bubbles in the finished plaster allowing air behind it.

This is a common symptom and may be as a result of application and materials chosen. The first primary characteristic of bare brick is its exceptional suction quality. IE draws in moisture. This can be a really problem with modern plasters as the product dries too quickly due to this suction. To combat this SBR sealers can be used but even this cannot stabilise the backing unless very thorough. 'Skinning out' the surface area with plasterboard and bonding adhesive tends to be the chosen solution these days because it leaves you with a stable surface to finish plaster and is an instant 'get flat' system. Best solution as you are now is a ready available fine filler. As to whether it will get worse, that depends on your view but it may change or appear elsewhere. As a guide for the future, ones best first coat is waterproof sand and cement. This will stabilise moisture content and brick suction in wall, particularly in an old solid brick and ''outside'' walls. Then when this has dried followup with relevant float and finish coats of plaster.

Hi Can i ask what backing plaster you used or was it sand and cement render.