Realising a Dream - 10 – Walls & Floor

With the building erected, all sparkling new, basic electrics installed, it’s ready for me to roll up my sleeves and get stuck in.

Outer Walls

First, checked all bolts for tightness, then squirt black mastic sealant into all joints between panels, uprights and the base from the inside. This improves water resistance and reduces draughts in the airspace between the studwork and the outer wall. This was a long, mucky and very tedious job.

Concrete is porous and soaks up water, that’s why it can look so dark after rainfall. All the concrete parts have within them steel reinforcement wire which rusts, when steel rusts it takes up a greater volume. When trapped in concrete it will eventually split the concrete causing structural damage. Or if near the surface, cause scabs of concrete to be ejected which leaves small craters showing rusty wire. This not only exacerbates the problem, it is an eyesore and will result in rust stains down the wall after rainfall.

To significantly reduce this problem and improve the life time of what is an investment, (it adds value to your property) external surfaces should be coated.

After allowing a period of time for the concrete parts to dry out after manufacture the walls were dusted down and primed with a wash of diluted PVA (recommended by the guy who assembled the building). This was followed by a coating of masonry paint designed to resist moisture and allow the escape of vapour.

Inner Walls

I had decided to split the internal space into three rooms, largest for the railway (naturally), second for a small workshop and a fiddle yard and the remaining section as a garden shed as shown in the plan below.

The studwork was built in a simple fashion using treated structural timber throughout, the partition between the railway room and the other two rooms was built more solidly as it would be taking half the weight of the ceiling beams from the railway and workshop rooms.

Cellular foam insulation was inserted within all the outside wall studwork but rock wool insulation in the dividing wall between rooms, I had plenty of rock wool that was stripped from the garage prior to demolition.

As the railway was going to pass through the partition walls in up to two places the studwork was kept away allowing soft ‘tunnelling’ to be possible after lining out was complete.

Railway room ceiling beams were reinforced with (herring bone) strapping between them to prevent twist and bolted to the studwork at the outer wall. The inner ends were supported by joist hangers at the dividing stud wall. The same approach was used for the workshop but without the need for strapping as the beams were much shorter.

Plaster board work was kept simple as I am not a plasterer, panels were screwed in place, the screws being sunk below the surface and filled. I used taper edged board, you can then fill and level the valley created by adjoining tapers. My plastering was then limited to filling in these valleys and sunken screws. A skilled plasterer would probably use square edged board, any discrepancies in level accommodated in the layer of applied plaster. I used paper (scrim) strip in the corners soaked in plaster to tidy and blend the walls together.

Same approach for the ceiling except no scrim, I used polystyrene coving to tidy up the wall to ceiling plaster board joints.

After painting there was an acceptable finish to the walls, not so good for the ceiling but good enough.

Insulation, air gap, studwork and plaster board reduced the internal dimensions by a nominal 1ft (30cm) in both width and length. The garden shed room partition wall surfaces were covered with off cuts of plasterboard to seal in the insulation.

All the plasterboard was then roller painted in white except where it was above scenic layout areas, there I used a very light blue with patches of white showing through in places to represent thin clouds.

The Partitioned Space

The adopted partitioning of the building showing the marshalling yard and workshop upper fiddle yard. Further multi-level baseboards occupy the central area of the railway room, including the cement works.



Flooring

The choice of flooring is worth considering, the options I considered was carpet tiles and laminate flooring. Carpet tiles can be bought used or new and I found them useful in my old garage which was lined out and heated. However although warmer to the feet when on a concrete floor, workshop dust and spillages soon make cleaning difficult.

Laminate flooring on the other hand with an insulated underlay of either foil/polystyrene laminate or fibreboard is much easier to clean and easily swept with brush and pan to find that little widget you just dropped. The only downside is that it has a hard almost brittle surface, which can cause one of two problems. If a model hits it from a metre or so up the model will break, if however you drop a hammer or similarly heavy object the floor will be the damaged.

I opted for laminate flooring with a fibreboard underlay as it soaked up floor imperfections easier and the weight of the layout framework will be high under legs for reasons apparent as I move onto baseboard construction.

Also considered and implemented was a layer of damp proof membrane plastic across the floor to reduce the effect of water ingress later on in the life of the building. Laminate flooring does not like moisture it will happily warp and repairing laminate flooring is difficult as it locks together on assembly.

Next, lighting, heating and power distribution, Jim.

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