Brick wall observatories?

[coatesg]

2 hours ago, JamesF said:

I don't believe this is true any more.  There are restrictions on height, positioning, number of floors and the area of land that may be covered by outbuildings, but I don't think the permitted development rights specify anything about the material used for construction of outbuildings.

James

Correct - it's about volume, size and position (and relative dimensions wrt the land it's on as well as other considerations). 

FWIW my dome sits on a 2ft height circular wall - easiest way to get it to the right height with the required strength!

[JamesF]

I wonder if thermalite blocks might be better than brick in terms of heat retention?  Less thermal mass (as well as being faster to build with and easier to handle), but would probably require a render skin to keep the damp out.

James

[souls33k3r]

That sounds like a good shout @JamesF, i'm sure someone wiser than me has already tried and tested, crashed and burned with this idea but i couldn't find any evidence of anyone ever trying out this way here in the UK.

 

[laser_jock99]

On 17/04/2018 at 12:03, rwg said:

Planning permission - Timber garden buildings typically don't need it. Brick built things typically do.

cheers,

Robin

Planning permission. Living on the edge of a National Park I chose a timber construction to fall in the 'shed' category.

[Rusted]

I have a [long] lifetime's experience of living and working in buildings with intolerable temperature swings.

The worst offender are arguably Welsh slate and dark coloured concrete roofing materials.

I cured a tar-felted, 4" thick concrete roof from soaring inside temperatures simply by covering it in shiny [scrap] aluminium.

Pebble-dashed, prefab, factory walls pushed temperatures towards the upper 30s C day and night for months.

Large skylights, lean-too greenhouses and south facing glass are thermal disaster areas.

As is roofing felt. NO thickness of insulation will help here. Just ask anybody who works or lives under it.

I've seen fortunes spent on desperate attempts to cool offices with felt roofs.

The coolest buildings materials are naturally white. Or heavily painted white.

As can be easily tested with the MkI human hand in any serious builder's merchant's outside stock. 

My own two story obs. building will eventually be clad in decorative, grooved plywood over a completely timber structure.

The 14' pier is a wide-based, timber pyramid built of 4x4s with local, upper reinforcement from plywood.

Foundations are all height-adjustable, pyramidal, concrete precast units, widely sold as carport anchors.

I defy a thief gaining entry to a 18mm [3/4"] thick, plywood clad shed unless it is made vulnerable by entrances, windows, locks or roofs.

Conversely, T&G clad sheds are hopelessly vulnerable to local attack. Or even just the weather.

If theft really bothers you on a vulnerable shed then fix weld-mesh to the interior with plenty of screws and washers. 

If cladding the outside then use coach bolts with domed heads.

I've done that with several workshop windows. If the mesh can be easily seen then only a vandal would break the glass just for the sake of it.

Nothing will get through weld-mesh except a JCB.  Galvanized is prettier and still affordable in big sheets. 

Doors, locks and windows are typical vulnerabilities even in underground concrete bunkers.

Some padlocks and their hasps have an open invitation in several spoken languages on YouTube.

[ollypenrice]

Of the six observatories here only one is built of blocks (rendered breeze blocks in UK parlance.) The rest are timber on either steel or timber frames. I'm not sure why I went for blocks on the odd one out. I guess I felt like a change and hadn't made a block wall before so I was curious. And there's less maintenance when it's done, of course.  However, if you're not a brickie they don't go up quickly, I can tell you! It did take me a while.

Walls:

Steel rolling roof and sides. (I made the tops of the walls and rail carriers in timber so I could easily lower them if I felt they were cropping the view too much.)

Rendered:

This works fine, but the timber ones do as well. The reduced maintenance is significant, though.

Like Sara I don't find the thermal mass/cool down to be any big deal. I have less thermal mass around the scopes than she does and it won't be quite as hot here but, none the less, it does routinely hit the mid thirties outside. In truth you simply can't have a solidly mounted fixed scope without a fair bit of dense, solid stuff to stand it on.

Olly

Edit: regarding building materials for observatories, I do have one firm opinion: galvanized corrugated steel is by far the best material. You can bolt it down so it won't tear off in the Mistrale, its lifetime is borderline geological, it is unaffected by UV, it just works. Anything else is less.

[Rusted]

18 hours ago, ollypenrice said:

Edit: regarding building materials for observatories, I do have one firm opinion: galvanized corrugated steel is by far the best material. You can bolt it down so it won't tear off in the Mistrale, its lifetime is borderline geological, it is unaffected by UV, it just works. Anything else is less.

I wonder how well it reflects the heat in sunlight when new and after weathering?

It is a popular material for grain silos around here. Shiny and bright to start with but it soon tones down to silvery-grey.

There is an unbelievable difference between polished aluminium and polished stainless steel.

The aluminium remains cool while the stainless steel gets "red hot" in sunshine.

[ollypenrice]

19 minutes ago, Rusted said:

I wonder how well it reflects the heat in sunlight when new and after weathering?

It is a popular material for grain silos around here. Shiny and bright to start with but it soon tones down to silvery-grey.

There is an unbelievable difference between polished aluminium and polished stainless steel.

The aluminium remains cool while the stainless steel gets "red hot" in sunshine.

I have an insulation layer under the steel anyway to avoid drips of condensation falling on the scopes. The galvanized finish does go dull but remains effective. My oldest is 14 years old, I think, and is rust free. It can be painted white, too, if so desired.

Olly

[nytecam]

Brick and blockwork can act as heatstore but may be need for security or fire protection reasons.  Protct sunfacing sides with shade, vegitation, climbers, white paint if practical.   I prefer to use timber framing and thin metal sheet for roof/dome which have low mass and cool quickly after dusk. See my dome build link below ;-)

 

Nytecam

[JamesF]

As I pointed out in Sara's rebuild thread, her obsy whilst having apparently solid walls actually uses hollow (clay?) "bricks".  Those will significantly reduce the thermal mass and the contained air will act to insulate the inside from the temperatures outside.

James