Wednesday, 16 April 2014

New Lintels for Old

Lintels are horizontal beams that run across the top of wall openings, such as doors and windows. They transfer the load of the wall above to the sides of the opening. We are all familiar with the re-enforced concrete lintels of modern construction.

At Balintore Castle most of the openings are topped by arches, which survive the test of time well: witness the Norman cathedrals which are still with us. The few lintels at Balintore Castle (8 in number) are unfortunately wood, and as water has poured into the building for many decades these are all suffering, to a greater or lesser extent, from dry rot.

Over the past few months, the wooden lintels have all been replaced by concrete ones. This has been a major job, but one which will keep the building standing well into the future. 

How do you take out a wooden lintel and put in a concrete one without a building falling down? Here's how. The silver attachment on top of the rather rusty accro-prop is called a "strong boy". This holds the wall up while the lintels are swapped - you can see the wooden lintel in the photo is in a very bad condition indeed.

strong boy supporting wall

Removing a lintel is no trivial task. It is embedded in a wall so the surrounding masonry has to be chopped out. Don't forget that the lintels in Balintore are massive. The one lying on the stairs below was above a drawing room window: a glove is shown for scale. This lintel is in pretty good nick, but there is dry rot at the ends.

wooden lintel removed from drawing room window

The wooden lintels above the bay windows were further connected by massive cast iron angle brackets: a glove is shown for scale. This made the task of getting the lintels out the wall even more complicated.

cast iron bracket for joining wooden lintels

Basement Lintel

You can see from the before photograph that this lintel at the bottom of the entrance tower in the basement was in an appalling condition.

before: wooden basement lintel

Here's the concrete replacement, photographed from the same side:

after: basement concrete lintel from front

Looking underneath you can see that three concrete lintels are required side-by-side to replace the massive old wooden one:

after: basement concrete lintel from back

Entrance Hall Lintel

The entrance hall lintel is also in a shocking state:

before: wooden entrance hall lintel from back

after: concrete entrance hall lintel from the front

after: concrete entrance hall lintel from the back

Three Drawing Room Window Lintels

before: wooden drawing room window lintels

after: concrete drawing room window lintels

Three Dressing Room Window Lintels

As the wall finished a foot or so above the dressing room window lintels, it was simpler to dismantle the top of the wall, replace the lintels and then rebuild:

during: first concrete lintel positioned after removing stone

after: concrete dressing room window lintels with wall above rebuilt

Thanks to Adam and Barrie (ably assisted by Andy) for all their hard work.

1 comment:

  1. I can appreciate the deep satisfaction of accomplishing these vital structural issues. Good work!