Restoring the roof of your period house

Old slate roof

Restoring the Roof of your Period House

Restoring and repairing the roof of your period house should be a priority over any other jobs on your list. A roof that allows even a small amount of water to leak into the fabric of the building can cause damage to the ceilings and timbers below. Over time leaks can result in damp, rot, and decay. Leave the problem too long and you’ll be looking at some very expensive repairs.

Your period house roof might use one type of material or a combination of several. Slate tiles are extremely common, as are clay tiles and metal sheeting made from lead, copper, or zinc.

Damaged Victorian Roof Tiles
On this Victorian slate tile roof, the ferrous nails have corroded and the slate tiles have slipped. Source: Surveyor’s Notebook

The style of your roof might be a straightforward pitch, a hipped roof or mansard roof, or a combination of different elements – for example, often a single pitch or flat room can be seen on parts of the building that extend from the main structure. You may have more decorative elements to maintain such as gable, dutch gable, or turrets. You may also have areas of the roof that are ‘flat’, or small flat gullies between the roof pitches.

Regular checks and maintenance

If the roof of your period property hasn’t yet developed any problems, we recommend you plan a regular maintenance schedule, at least twice a year.

Start by walking around the property and looking for any materials on the ground that may have come from the roof. Some examples are slate or mortar. Ask your window cleaner or local handyman to check the gutters for this kind of debris. This is usually a good sign that the roof needs work.

Carefully view the roof through binoculars – you might need to stand back from the property, in the garden, a neighbor’s garden or across the street to get a good look. Keep an eye out for missing or slipped tiles, missing or cracked ridge tiles or damaged mortar/cement, or corroded metal flashing. Problems frequently occur at the corners of the roof so check these with extra care.

Missing roof ridge tiles
Ridge tiles are the thinner tiles that sit on the points of the roof. Here, a ridge tile is missing and underneath you can see loose, flaky cement. Source: Daniel’s Roof
Broken Victorian roof tiles
Here, a number of the roof tiles have slipped and left a large gaping hole! Source: Society for the Protection of Ancient Buildings
Examine the corners and joints of the roof carefully - here, the metal flashing around a chimney has badly rusted. Source: Lyons Contracting
Examine the corners and joints of the roof carefully – here, the metal flashing around a chimney has badly rusted. Source: Lyons Contracting

Check the Loft

If you can access the underside of your roof (e.g. by visiting the loft) check this carefully for crumbling or broken roof materials. Check the roof timbers – if they are damp or rotten, try to locate where the water has seeped through. Look for water stains and if you do spot them, you’ll need to know if they’re current or an old (fixed) problem. Now you should carry out your checks while it is raining heavily, or just after. Turn off any attic lighting and look for any cracks of daylight coming through, indicating a hole in the roof.

Flat roofs

Flat roofs can be a particular problem in period properties. Typically they will be covered by copper, zinc, lead, bitumen or asphalt, but as the water cannot drain away as efficiently as it does with a sloping roof, it can start to pool on the surface for long periods of time (known as ponding) and eventually cause a breach.

'Ponding' on a flat roof - this picture was taken a full week after rain. Source: Sparks Home Inspector
‘Ponding’ on a flat roof – this picture was taken a full week after the rain. Source: Sparks Home Inspector

A flat roof actually should have a slight incline (at least 1 in 80) to help the water disperse but this is not always the case – especially if the area is, for example, a gully between several pitched parts of the roof. Additionally, the timber joists beneath the roof should be sufficient enough to withstand any sagging, the cause of water pooling. Once the water pools, even the tiniest pinprick can start to allow the water to seep into your property.

If you can access any flat areas safely without walking on them, check them carefully for splits, cracks, or holes. Also, check for areas where the water has started to pool. Again check the roof from below if you can, to see if the water has started to come through. If it’s impractical to check your flat roof yourself, do invest in a regular check by a professional as this type of roof has huge potential to fail and cause substantial damage.

Tackling roof problems

How you tackle problems with your roof really depends on the nature of the problem. Many repairs can be carried out by an experienced roofer. If however, you spot major structural problems such as rotting timber, you should employ the services of a surveyor or structural engineer and a carpenter. Someone with experience in working on period homes. If the timbers have rotted, don’t try to cover them up with a new roof. They may not be able to support their weight. It is very difficult to repair them once the new roof has been put in place.

Flat Roofs

For flat roofs and gullies, don’t feel like you have to replace the materials like for like in order to faithfully restore your period home to its former glory. Past materials and methods can be less effective than modern alternatives and have a limited lifespan. Remember that your roof protects the beautiful period property that you are also trying to restore or maintain and so you need to ensure it offers the best possible protection. Fiberglass roofing such as that offered by UK fiberglass roofing expert Topseal is a very good choice as a replacement for lead or copper. It can be used to completely cover flat roofs and also for gutter linings and even complex architectural detail work.

In past projects, we have seen flat roofs coated by Topseal with Fibreglass to ensure a completely waterproof, long-lasting protective layer. This layer will stand up to heavy rainfall. They have also managed projects in listed buildings with fiberglass roofing simulating rolled joints without seams and color matching (achieved by applying a topcoat in copper green or lead grey) to ensure a sympathetic end result (view Topseal’s gallery for examples). These new materials offer the durability and longlasting performance that you need.

Adding light

Period houses tend to have generous roof space and most homeowners will convert this to a living area. Unlike modern properties, the roofspace may not need boarding up. Victorian attics would often be used by the serving staff and would have floorboards and even fireplaces. However, they can be rather dull and dingey – and you might want to consider adding a roof window. It’s important to choose a style that fits the character of your house – so, for example, Fakro manufactures a whole range of roof window designs, including beautiful arc windows and top windows that are more in keeping with period property style.

Uncredited feature image source: C Verrone roofing Connecticut

That sums up Restoring the Roof of Your Period House. If you have anything to add, comment below!

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