A Good Example of a Bad Window Hinges Design

27 Apr

A Good Example of a Bad Window Hinges Design

Recently we came across casement window hinges which caused the majority of problems with the windows. Timber frame to which the hinges were attached, almost fully decayed. The owner of the property could not open most of the upper floor windows. It was a rear occasion where a flawed design caused the rot.

Thermal bridges created by hinges

Exterior window hinges considerably reduce a window maintenance cycle.

This happens because more cold and heat is transferred into the wooden frames with screws and the hinge plates. Metal has higher thermal conductivity than wood. The process of temperature deviations in one material through another is also known as thermal bridge.

Because of the thermal bridge, a corner of a bottom timber rail where a hinge plate attaches to a casement will be the first place for paintwork to crack and let moisture in.

Moisture will create a perfect condition for rust and rot to develop quickly.

Thermal bridges created by screw or nail
Here is good Illustration of what is thermal bridges from insulation industry.
Reference: Thermal Impact of Fasteners in
High-Performance Wood-Framed Walls
bad window hinges design
decayed window corder where hinge was affixed

14+ centimetres lever arm

The pin of the hinge around which the casement is pivoting is located 7 centimetres away from the place where the hinge is attached to the window frame and casement. This creates an approximately 14 centimetres lever arm, increasing pressure on all joints when you open the window and slowly breaking the timber frame and letting more moisture in.

full hinge length when window is open
width from hinge pin to hinge base plate

How to deal with consequences of bad window hinges design

  • First of all, you should remove all rotten & decayed timber.

  • Remove old hinges.

  • Repair wooden window with new timber like Accoya or Tricoya.

  • If your property is not Grade 2 listed, install new ball bearing window hinges by cutting the new mortise in the timber frame and casement. 

  • Please note: If you live in a Grade 2 listed property, you need to keep the old hinges and renovate them by removing all layers of old paint and erosion and lubricating the mechanism. The excess lubricant should be removed before painting. To avoid rusting, use galvanised screws to fix hinges back to the window.
how to repair timber after bad hinge

How to remove old layers of paint and loosen hinges:

crape off paint from hinge

1. Scrape off paint

Use a Stanley knife or scraper to scrape off the paint. If you want to make it spotless, use some fine-grit sponge abrasive.

Use WD-40 to remove rust from hinge

2. Use WD-40

Spray some WD-40 onto the pin. Now bend two moving parts of the hinge from fully closed to fully open until all bits of paint and rust are removed.

clean off access of rust and wd-40 with white spirit

3. Clean before painting

Remove excess WD-40 and rust with white spirit before painting. This prevents stains from coming through after painting. If you have leftovers of white spirit, you can read here on how to dispose of it.

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