Design instructions to stop the disturbance to flooring due to movement of screeds in heated floors
In
contrast to normal screed constructions, heated screeds (screeds placed over
under floor heating) need certain special design concerns. There are high
chances for the screed to create potential serviceability difficulties, except
suitable stress release measures are integrated right at the design phase. The reason
for these problems is that heating elements for under floor heating system are
inserted in the screed.
One of the most common problems is the disturbance to flooring because of continuous screed movements which came across in heated screeds. Movement of the screeds has been yet unavoidable and it will last all over the life of the floor as the heated screeds follow the ‘floating screed construction’ in which the screed is isolated through the base by means of a layer of thermal insulation. This sort of construction has been implemented to prevent the heat from escaping through the base and to maintain the efficiency. But, the separation of the screed from the base will assists the screeds to comprehend their full movement potential for instance as the screeds enlarge and contract due to the change in the temperature of the heating elements.
On the other hand as it is not practically conceivable to control these movements completely, but the best decision is to design the screed in such a manner as to entirely accommodate the movements to stop disturbance to the screed and the flooring.
Certain specific recommendations has been laid out by DIN 18560 which may be implemented at the design phase for heated screeds:
§ Perimeter bay size of 40 sq.m
§ Perimeter maximum bay measurement to 8m
§ Manage bay sizes with separate heating circuits
§ Offer thorough isolation for bay joints
§ Isolate the limits and projections with joints that are capable of a movement of 5mm
§ Simplified the number of elements which are passing over the joints
§ Make available support for cementitious screeds where rigid flooring has to be applied
It is always sensible to search for specialist advice while going for under floor heating systems.
One of the most common problems is the disturbance to flooring because of continuous screed movements which came across in heated screeds. Movement of the screeds has been yet unavoidable and it will last all over the life of the floor as the heated screeds follow the ‘floating screed construction’ in which the screed is isolated through the base by means of a layer of thermal insulation. This sort of construction has been implemented to prevent the heat from escaping through the base and to maintain the efficiency. But, the separation of the screed from the base will assists the screeds to comprehend their full movement potential for instance as the screeds enlarge and contract due to the change in the temperature of the heating elements.
On the other hand as it is not practically conceivable to control these movements completely, but the best decision is to design the screed in such a manner as to entirely accommodate the movements to stop disturbance to the screed and the flooring.
Certain specific recommendations has been laid out by DIN 18560 which may be implemented at the design phase for heated screeds:
§ Perimeter bay size of 40 sq.m
§ Perimeter maximum bay measurement to 8m
§ Manage bay sizes with separate heating circuits
§ Offer thorough isolation for bay joints
§ Isolate the limits and projections with joints that are capable of a movement of 5mm
§ Simplified the number of elements which are passing over the joints
§ Make available support for cementitious screeds where rigid flooring has to be applied
It is always sensible to search for specialist advice while going for under floor heating systems.