PERFORMANCE.

Nowadays timber windows and doors have to perform against a number of criteria ;

• Energy-efficiency
• Draught-proofing
• Security
• Noise reduction
• Low maintenance
• Durability

CJS Exteriors only specify timber products that are fully factory pre-finished, this process includes a pre-preservative timber base coat, primer coat followed by two coats of water based micro-porous paint or stain, these coatings are all applied in a dry and sealed factory condition. On site painting or staining achieves a much lower level of protection and humidity and moisture levels present during an on site application often damage the coating durability and subsequently reduces the life span of the window or door.

CJS only specify high quality, slow grown redwood with a high proportion of heartwood and if you combine these facts with the use of engineered timber or semi-engineered finger-jointing the average life expectency of the window will rise from 30 years to 45 years and the required maintenance period will increase from 5 to 8 years, this has allowed more responsibility when it comes to timber selection, for example, hardwoods in their raw state are generally more durable than softwoods which often initially encourages our Customers to select hardwood over softwood, however, the fundamental difference in todays production methods is the construction and protection processes applied to the timber prior to installation and it is worth remembering that the majority of timber used in domestic household construction and joinery during the last 100 years was softwood. Great care must be taken when selecting hardwoods due to the very low amounts of timber available with traceable certification or chain of custody certification.

Factory glazing windows and doors also provides a significant difference in the long term performance of the sealed unit, breakdown of the IGU ( insulating glazed unit ) is almost 30% less likely than dry glazing timber windows and doors on site and timber is also marginly more thermally efficient than PVC. CJS offer a standard specification for our timber windows and doors with 24mm sealed units, double glazed, low Emissivity soft-coated glass and argon filled, this provides a U-value for the IGU of 1.1 Wm2k, the compliance level for PVC windows under Part "L" for Building Regulations is 2.0 Wm2k, most double glazing companies offer a rating nearer 1.8 Wm2k, this equates to a 39% efficiency gain over an accepted industry standard.