Part 7 - Ridge Tiles

Ridge tiles are a special tile to do a special job €“ they sit at the very highest point of the roof and bring together the two sides.

Ridge tiles get the worst of the weather as they stick up by themselves so have to be a little special to do their job effectively.  Therefore fitting them takes a little extra care and attention to allow them to do their job perfectly.

Ridge basics

Modern ridge tiles are most frequently in one of two profiles, though others are available.  These are half-round and angular.  The angular ridge tiles tend to be used with slate roofs in particular.  Ridge tiles that also incorporate ventilation are an important option that may be right for your roof as well.

Where a roof has a design involving the meeting of two ridges, for example a horizontal ridge meeting an angled hip ridge or where two horizontal ridges join, ridge tiles may need to be cut.  Otherwise, ridge tiles are normally fixed as supplied using mortar on both sides of the roof, though some manufacturers have created a method that doesn't require mortar.

Other special shapes of ridge tiles include mono ridges, modern ridges, security ridges, stop end ridges and concrete segmental ridge tiles.

Mortar bonded ridge tiles

Of the various styles of ridge tiles, fixing them into place with mortar is still the most popular choice.  This means that the tiles have to seal the top of the roof and do this by overlapping the slates or tiles on each side by a minimum of 75mm.  For flat faced tiles or slate, a stiff mortar of 1:3 cement to sharp sand ratio is used along the top of the tiles.  For tiles that have a deep profile, these recesses are normally built up with small slips of flat tile before the mortar is introduced.

Another style of mortar bonding is when half-round ridge tiles are used.  Here a solid bed of mortar is used at the end of the ridge tiles to fill up the gap where the tile meets the roof tile.  A piece of flat tile, or a slip, is used to bridge the gap between the roof tiles and the ridge tiles and mortar is then added into this.

Step by step

Remember to mix your mortar before you venture up onto the roof.  The 1:3 ratio is also described as being thick enough to stand up 7.5cm without slumping over.  You can then put it into a bucket to safely carry up to the roof.

Dampen the bottom of the ridge tiles and also the corresponding roof tiles with warm water.

Spread a smooth line of the mortar you made 5cm wide at the point where you will place the ridge tile.  Only cover enough of an area in one go that you can lay the tiles on, otherwise the mortar will harden and be useless.

Firmly press the tile into place.  Once you have three or four tiles in their location, tap down on the tiles with a rubber mallet gently to compact the mortar underneath.  This ensures a good hold.  Also, check the level around every third or fourth tile to make sure your line is straight before the mortar sets.

Use a mortar trowel to remove any excess mortar from under or between the tiles and put this back into your bucket.  Continue to lay the next section of tiles, avoiding stepping on the ones just laid for at least 48 hours.

When you are laying tiles, these general rules will apply to almost all types but ensure you check the instructions from your manufacturer for any tile-specific information.  You may also need to install dentil slips or other spacers depending on the slope of your roof and the design you are aiming for, so check this out beforehand.

Remember safety €“ don't lay tiles in the rain or if it is forecast rain in the next 48 hours.  If it rains unexpectedly, cover the tiles with sacking or carpet to stop the mortar washing away and get down off the roof.  Remember to only work on a roof if you are confident doing so, don't do the job alone and make sure you have proper support across the roof, not merely a ladder.

Mechanical systems

Mechanical systems are a newer invention that negate the need for mortar by using a fixing system to keep the ridge tile in place.  These typically consist of:

• Side sealing pieces that are laid along the side of the ridge tile. These provide the deal between roof material and ridge tile and can be bought in styles that work with different profiles and materials
• End sealing pieces that sit at the end of each ridge tile to seal the gap to the next one
• Special ridge board that is mounted above the apex of the trusses to support the fixings. This needs careful positioning to provide a space under the ridge tiles to put the fixings in place
• Fixing nails or screws plus seal washers, normally made from aluminium or other non-corroding material

These mechanical systems are perfect for single ridges but can become a little more complicated where two ridges come together so a mortar system may be more appropriate in these situations.

Ventilated tiles

Ventilated ridge tiles are commonly available to work with fibre cement slates, concrete tiles and slate roof materials.  It allows an unbroken ridge line but also ventilation into the space below, without letting in any water.  Most manufacturers make them so that they are maintenance free and work to avoid condensation in the loft and its associated problems in most roofing systems.  Each kit will have its own instructions as to the specifics of fitting them so ensure the best finish.

Conclusion

Ridge tiles are the crowning glory of the roof but also one of the most common elements to suffer problems.  These are things such as the mortar coming away that then lets water in or the mortar not being strong enough to cope with the extremes of weather.  So whether using mortar or a mechanical fixing, ensure that you install the best possible tiles to make your roof keep its crown in place for the longest possible time.

 

Reference URLs

http://www.marleyeternit.co.uk/Roofing/Fittings-And-Accessories/Concrete-Tile-Fittings.aspx

http://www.practicaldiy.com/general-building/roofing/fixing-ridge-tiles.php

<ahref="http: www.diydata.com="" general_building="" roofing="" fixing_ridge_tiles.php"="">http://www.diydata.com/general_building/roofing/fixing_ridge_tiles.php

 

http://www.ehow.co.uk/how_7206732_lay-ridge-tiles.html

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