If you do have a written report, this is one done recently, here as an example of what you could expect

 

Roof Report

The condition of the internal woodwork of the roof both structural and minor where it can be seen is in good sound condition and adequate for a thatched roof. Access was only possible to the two end bays. A new softwood structure has been cast over the existing timbers when it was thatched approximately 13 years ago. Evidence of past woodworm attack on the old timbers is minimal and does not appear to be active.

The main roof  elevations are of water reed up to barge boards and generally of good quality and condition apart from the garden side under the chimneys which are starting to deteriorate. The capping strips to the barge boards are in places rotting.

The ridge is a cut block pattern wrap over held by Hazel spars and liggers. This is showing signs of  wear within tolerable levels. The ridge of a thatch roof of this type and position would normally be expected to last for 15 - 20 years although some signs of wear may be apparent after 10 years. This does not affect the water proofing, just the aesthetic appearance.

Flashings  to chimneys are of lead apart from the strip on the church side mid chimney, this is galvanised steel sheet and showing rust stains.

Recommendations

The ridge should be anticipated as due for renewal within five years, this would include new netting and flashing replacement as needed, and normally repairs to any small faults found on the main roof. However the wear under the chimneys is in my opinion excessive on a roof of this age, and although it is normal for the area under chimneys to deteriorate first it may be necessary to re thatch these areas at the same time as the ridge is replaced. The cause is the relatively fine texture of the reed used and the sheltered location of the cottage.

While not unusual a slime mould has covered the church side elevation, I suggest keeping this in check by spraying with a proprietary path moss cleaning agent.

While the chimney stacks are relatively sound for their age I would strongly suggest linings be inserted in particular if solid fuel is used.*

The existing roof void access is very small, and in the mid section sealed. 600mm x 900mm is advised by fire brigades ensuring that access can be gained to all roof void areas.*

* See chimney fire on the web site ( Chimney Fire )
Requiring immediate attention

Removal of the Ivy from the roof and preferably kept cut back 1 metre from the thatch.

Replacement of the barge board capping strips before water damage occurs to the boards, preservative treatment should be applied to external surfaces of the boards themselves.

Comments

Although the ridge would be expected to remain watertight for longer than 5 years it will quite rapidly begin to look increasingly untidy. The thatch has been applied over a polythene sheet, this can cause internal condensation but the air flow through this area where checked is more than adequate. Normally I would suggest the cutting of each panel to allow air flow, in this case it is not needed.

The air movement within the roof void however will cool the ceiling surfaces and I would suggest that adequate insulating material be installed to this area.

Anticipated Costs

To ridge, and repair should be within  £8,000 Please obtain at least three quotations from thatchers who preferably are members of national or county thatchers associations. I would also suggest having a look at work of a similar nature that they have done before accepting an estimate. Please ensure that estimates are asked for with verifiable specifications of at least material type and thickness.

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