Our Lord in the Attic: A Case Study
Wooden floors
The visitors are allowed to walk over the floors in each room. The wooden floors are an important feature in this building. The structure of most is original, although maintenance work has been carried out throughout the centuries. Walking through this building over the floors and hearing the creaking of the wood is considered essential to the visitors' experience.
Description
Many floor areas in the house are made from wood. Pine boards with a width of 25 cm and thickness of 30-35 mm are connected by a ‘groove-key’ construction. Both boards have groves and are connected using small oak wooden keys. Nails are used to fix the planks to the supporting beams. In many areas, the floor is also the ceiling of the space underneath it.
The floors are not level but slope down towards the alley. This sagging caused small splits between floor boards and beams, although the natural drying and shrinkage of wood is also a contributing factor. The floorboards shrink considerably within the first 5 years after being placed, causing splitting. These first splits usually will have been filled in with strips of wood, especially when the floor was in view. As wooden planks dry, they curve slightly. A good carpenter would have anticipated this by positioning the planks with the rounded side up, so that when the wood shrinks, the plank would become level. However, in several areas in the house, wooden planks are positioned with the hollow side up. 
This could be a result of replacement of the original wooden planks by ‘new’ 17th century ones or by turning the planks over, as the bottom side of a plank would be smoother and cleaner then the top.
Small white glazed tiles are used for skirting the walls and for tiling the walls of most of the staircases. These typical tiles were produced from 1600-1900.
Listen to the architect explaining some of the features of this house:
Condition of the wooden floors
Different types of damage can be observed (this was recorded in a condition assessment in 2006):
- Pine, being a soft wood, is easily chipped, especially at areas with extensive walking;
- Planks are worn - wear and tear has lead to exposure of the iron nails that are used to fix the planks to the structural beams.
- In some area the grooves between the planks have increased, thereby exposing the keys. At a certain point the oak keys between the planks will act as a lever and the pine surface will chip off. This type of damage starts occurring when approximately 3 mm of the original surface is worn away.
- Areas that are difficult to clean show a dark brown deposition and parts of the skirting boards (often tiled) are chipped;
- Near humidifiers water stains can be observed.
In the past gaps between floor planks would have been filled with strips of wood and sometimes wood putty. Heavily worn planks would have been repositioned to areas of lesser use within the building, or even replaced by old planks from a demolition site. In 1938 it was recorded that worn out floor parts in the church were replaced with wood from a building that was torn down.
Of particular concern is the wear in certain areas, where the decrease in thickness of the wood has potentially created structurally unsound situations. A more detailed survey of the wooden floors is planned, which will identify the exact extent of this problem. The areas of concern are concentrated on the first gallery of the church, specifically at the top of the stairs leading from the church main floor and right next to the organ. The first area is a turning point and this obviously results in more abrasion. The other point is the spot where the organist jumps down from his high seat and immediately turns.