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Roof Shutters

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Roof Shutters

#1

Roof Shutters

Stephen Shepherd in the State of Deseret

>I am in the process of making shutters for roof slots in this observatory, base and meridian house, originally built in 1853. This is a reproduction of the building from original photographs.

The slots on the roof are opened to make celestial observations, transit of stars and planets across the meridian. I am constructing the shutters and am in a quandary as to what type of joint to use between the boards?

There are battens on the back and the iron strap hinges across the front on one and across the back of another. These hold the boards together.

I am considering Tongue and Groove, grooves and spline or half lapped rabbit joint. I will bead the edges to reduce warping and to give a drip edge (on the inside) to shed water.

Which joint would weather best?

Stephen


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Re: Roof Shutters

#2

Re: Roof Shutters

Kevin French, Antrim, NH

>I was just telling someone the other day we just don't have enough talk about 'Celestial Observations' here.

I've used 'Ship Lap' on the side of my old barn but not sure how that would work in your application. I would think that you should get a wider, stronger joint with a Rabbet over a T&G.

Re: Roof Shutters

#3

Ellis Walentine

At a loss, Stephen

Ellis Walentine

>Any joint you make will allow water to get into the spaces between adjacent boards and eventually rot the tongues or rabbets or whatever. I keep thinking that the time-honored concept of roof tiles might be the best guiding principle here. In other words, might there be a way to overlap the boards in a way that produces peaks and valleys, so water will drain naturally and completely instead of getting caught up in the tight spaces of a t&g joint?

I have no idea what the historical precedents are for this type of construction.

Ellis

Re: Roof Shutters

#4

Re: At a loss, Stephen

Stephen Shepherd in the State of Deseret

>Kevin came up with the best suggestion, the lapped rabate joint will be the strongest and has the best chance of surviving in the weather and shed the water.

The ship lap idea is traditional but can't use it here. However I am going to extend the nicking iron to groove the rabate on the inside edge to form a small groove to encourage the water to shed.

Out here we don't have much of a rain problem, dry mountain desert, but we do get a lot of snow so melting will be a problem.

I am going to cheat and put flags in my joints. Now I know it is a poor cooper that 'flages' their joints but in this case I will use any protection I can get.

Flags or cattail leaves will swell up in contact with water and fill the joint and prevent leaks. Being a water loving plant it tolerates being wet and dry and does not rot.

Stephen

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