Building Exterior Insulation Finishing System
What are the regulations for Exterior Insulation Finishing System?
(1) If there is no cavity between the sheath wall and the outer cladding, the insulation material of the Exterior Insulation Finishing System shall comply with the following provisions:
1) Residential Construction:
①When the building height is more than 100m, the combustion performance of thermal insulation material should be grade A.
②When the building height is more than 27m, but less than 100m, the combustion performance of thermal insulation materials should not be lower than B1.
③When the building height is no more than 27m, the combustion performance of thermal insulation materials should not be lower than B2.
2) Except for residential buildings and buildings with densely populated places, other buildings:
①When the building height is more than 50m, the combustion performance of thermal insulation material shall be grade A.
②When the building height is more than 24m, but less than 50m, the combustion performance of thermal insulation materials should not be lower than B1 level.
③When the building height is no more than 24m, the combustion performance of thermal insulation materials should not be lower than B2.
(2) In addition to buildings with densely populated places, the Thermal Insulation Material for the wall system with cavities between the sheath wall and cladding of the buildings shall comply with the following provisions:
1) when the height of the building is greater than 24m, the combustion performance of the thermal insulation material shall be grade A.
2) when the building height is no more than 24m, the combustion performance of thermal insulation materials should not be lower than B1 level.
All wall moisture problems must be resolved before external insulation are installed on the wall. Exterior Insulation cannot be used to cover or hide moisture, as this can cause a series of problems in the future.To install the EWI system, we should install the Exterior Insulation first, which needs to be fixed by some mechanical fixings and adhesive at the same time.Then protective layers of render or cladding, The finish can be smooth, textured or painted, tiled, panelled, pebble-dashed or with bricks.
To prevent condensation, recessed areas around windows must be insulated as well as the walls – with the depth of insulation depending on the width of the window frame.
All external piping and other fittings need to be removed or replaced.The window sill and roof overhang should extend over the exterior insulation.Sometimes extra window sills will be added to avoid the trouble of replacing the original one.
Cladding or render?
Cladding comes in a variety of beautiful colors and styles, timber panels or shingles, stone or clay tiles, aluminium panels or a brick finish.
Render can be either a thick sand and cement mix applied over a wire mesh or a thinner, lighter cement over a strong fibre mesh. It is generally less expensive than cladding.
As the occurrence of a number of building insulation fire events, triggered the introspection of all walks of life.The fire class of Building Insulation has aroused the attention of the industry. However, many insulation fires are caused during the construction process, such as: welding, open fire, and bad construction habits,etc. Some materials produce droplets and toxic smoke in the combustion process, at the same time the release of CFCS, HFCS, freon and other gases also have harmful effect to the environment.
To this end, the Ministry of Housing and Urban-rural development and the Ministry of Public Security jointly issued on September 25, 2009 the "Interim Provisions on Fire Prevention of External Thermal Insulation Systems and Exterior Wall Decoration for Residential Buildings" reported by The Public Security Department and The Transport Sector  No. 46 Notice.Thermal insulation possess better fire performance and thermal insulation performance can win the market.
(the following text is from the Code No. 10J121 of Building Construction With External Wall Insulation, China Building Standards Design and Research Institute)
1. System structure mainly includes: bonding layer, insulation layer, render layer, cladding layer and accessories.The finishing layer shall be made of decorative mortar and other light functional coatings or water-resistant exterior wall coatings with good air permeability.
2. Rock wool board external thermal insulation system, with advantages of low thermal conductivity, good air permeability and high combustion performance, can be applied to energy-saving and thermal insulation construction of the external walls of new, expanded and rebuilt residential buildings and public buildings, including external thermal insulation, non-transparent curtain wall thermal insulation and fire isolation belt of EPS external thermal insulation system.