Dry Verge Technology

Technical Article

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INTRODUCTION

We have recently been contacted by a home owner who has had problems with fascia boards where these are being used as overcladding, a subject we have talked about previously in one of our articles. Whilst carrying out the work to replace the fascia and soffit boards he came across problems with the cement verge that is to the end of the roof allowing water in. Whilst this cement technique has been used for many years there are now other alternatives available. Dry Verges are considered in the following article.

Cement verge	If you look closely you can see cracks to the left hand side that have been filled in with cement mortar. It is only a matter of time before they open up again.

This is a cement verge which has been clipped which tends to happen in high wind areas. To be sure the tiles dont lift clips also tend to be in areas where cracking can occur to the verge.	Dry verge system. Interesting lack of skill to the fascia and soffit board with the hole opening in it.

Dry verge at the ridge level	Cement verge with smaller tiles

Gaps left for the water to get in	Close up of gaps	Dry Verge

SYNOPSIS

For many years we have used cement at the verge of our roofs to fill in the gap at the end of the tile. The problem with this is that cement is traditionally being used which cracks over time and allows water in. The water can then cause deterioration to the adjoining baton which holds the roof tiles or slates in place. A way around this is to use dry verge technology which is a plastic shoe that fits on the edge of the verge and stops the dampness getting in. The solving of this problem when we researched it further seems to lead to other problems.

CONSTRUCTION SUMMARY

Cement verges have been used for many years and was almost the introduction of cement in the War Years. A typical house may look as follows:

External

This is a fairly common construction for a new property on good quality ground and it is typical of the majority of houses subject to local variations such as slates rather than concrete tile roofs or pantile roofs in some areas are required such as Norfolk and Suffolk. We are going to look at the verge of where the tile is.

We have used the term assumed' as we have not opened up the structure.

EXECUTIVE SUMMARY

Executive summaries are always dangerous as they try and encapsulate relatively complex problems in a few precise and succinct words. Having said that here is our executive summary and recommendations:

Whilst dry verge technology initially sounds to be a good idea in that the cement verges are no longer exposed and subject to cracking and deterioration eventually allowing dampness in. A dry verge, or a plastic verge or shoe can resolve the problems that can occur with the deterioration of the cement however if no thought is given to the projection the rain dripping off it does or doesn't have a proper drip it can hit windowsills below and we are aware of several complaints that have occurred due to the drips hitting the windowsill below and therefore keeping the occupants awake at night. We have also equally heard of the drips all occurring in one area and causing pattern staining to the brickwork below. A solution therefore would be to have pre-defined drip areas as we do think the advantages of having a dry verge and a clip stopping the deterioration of the cement as well as holding the tile verge in place and stopping deterioration of any batons would be well worthwhile. The dry verges do give an alternative to the traditional waterbedded verges, they too have problems.

Time Line A brief history of verges

This is where we look at how verges have progressed over the years. This is a general look, there will be specific variations subject to each area which is why you do need a Surveyor to look at your property.

INSPECTION

On a building survey the Surveyor should inspect visually externally and internally. Externally to see if there is any cracking in the cement verge and internally to see if there is any dampness getting in.

SURVEY FINDINGS

The dry verges certainly reduce the risk of the batons getting damp and the cement cracking. They do in themselves seem to have a problem as they do drip onto the walls below which can be particularly annoying if you have a bedroom windowsill beneath it. We have seen several complaints where this has kept people awake at night.