Talk:Key:roof:material

Plants

I think the newly added value "plants" is badly chosen - it's impossible to tell from the value itself that it is supposed to represent a "roof" (I'm also not sure whether it can actually be called that) as shown in the picture. --Tordanik 14:51, 16 June 2013 (UTC)

That is not a roof at all.

But what about a green roof, (live) sod roof, living roof or, roof garden? —Michael Z. 2014-10-09 21:26 z

I concur. Similarly, "gravel" - the gravel isn't the roof, it merely covers it. The roof is actually made of something else (e.g. concrete). --John Grubb (talk) 09:19, 4 September 2018 (UTC)

I agree. We should try to reach a consensus on how to tag green roofs. Green roof on Wikipedia. We should make the distinction between at least four types:

• green_extensive (thin layer of soil, in northern Europe often planted with sedum - succulents)
• green_intensive (thicker layer of soil, varied vegetation, higher price and possibly more maintenance)
• roof_garden (Both for plants and for people to stay on)
• grass (The traditional grass roof. could be classified to be a quite similar to the extensive roof, but the vegetation type is specified)

Also see two examples of mapping of green roofs :

• Chicago https://data.cityofchicago.org/Environment-Sustainable-Development/Green-Roofs-Map/u23m-pa73
• London https://livingroofs.org/london-map-green-roof-boroughs/london-borough-havering/

-MortenLange (talk) 20:48, 5 August 2019 (UTC)

Default roof material

What is the default roof material? Presumably the same material as the building[:part] itself? --Abbafei (talk) 06:49, 29 December 2014 (UTC)

I don't think there is a standardized default material at the moment. My own implementation prioritizes the roof:material on the individual building:part, then falls back to that of the enclosing building, and ultimately defaults to a tiled roof. A case could be made to make the default dependent on the building material, or even the country/region instead. --Tordanik 17:41, 31 December 2014 (UTC)

Shade Cloth

Added shadecloth - used in warmer climates. As well as covering plants it is also used for play areas to reduce the exposure to sun light. Warin61 (talk) 23:00, 9 September 2015 (UTC)

Plastic, asphalt

Plastic (PE or similar) roofs are common to cover garden huts etc. here. I will add roof:material=plastic for this, it is already used 142x. It looks similar to roof:material=eternit, but it's usually partly transparent.

I also want to add a similar one to plastic and bitumen, but made of asphalt. This is similar to tar_paper, but it is usually corrugated, stronger and doesn't need the underside covered continuously (sorry, I couldn't find the English word). It is clearly distinct from tar paper. I propose material=asphalt, it has 90 uses in taginfo. --V0174 (talk) 11:46, 3 December 2016 (UTC)

I too am considering that tar_paper is perhaps too all-encompassing. In simple terms, in the UK a bituminous fibre-based sheet is placed on the roof before the tiles or slates go on (tar_paper) but when the bitumen-impregnated fibre sheet is used as the actual exterior roof material it is reinforced with the addition of asphalt and an aggregate layer, having a rough, hard-wearing texture and is known colloquially in the UK as roofing felt. Perhaps the addition of roof:material=roofing_felt (or similar distinctive tag) would allow for clear identification between the two materials? Whilst tar_paper does indeed cover it there is a significant distinction between sheeting intended to form an impermeable membrane beneath slates/tiles, etc. and sheeting designed to form the roof layer exposed to the sky.

https://en.wikipedia.org/wiki/Tar_paper https://en.wikipedia.org/wiki/Asphalt_roll_roofing (what in the UK is commonly colloquially referred to as "roofing felt")

Edit: A further thought occurs that, when roofing felt is applied it is usually over wooden boards or the like so presumably the correct tagging would be something like roof:material=wood, roof:surface=roofing_felt/tar_paper...? Second edit: see roof:structure proposal below. --John Grubb (talk) 04:54, 6 August 2019 (UTC)

--John Grubb (talk) 07:50, 2 September 2018 (UTC)

Asphalt Shingles

An asphalt shingle is a type of wall or roof shingle that uses asphalt for waterproofing. It is one of the most widely used roofing covers in North America.[1]

roof:structure

I recently re-read the building:material= section of the Wiki, having received a notification that the page had been updated, and note that it now refers to previously unknown (to me) tags of building:structure and building:cladding. Structure holds the material that the building is constructed from (i.e. load-bearing, be it brick, metal framing, wood frame, etc.) and Cladding holds the exterior finish (i.e. the decoration, such as rendering, stonework, brick facing, etc.).

Would it not then be natural and consistent to introduce roof:structure to the OSMWiki "roof" section for detailed building mapping, where the structure is known, alongside roof:material? I'm experimenting with roof:structure=wood_frame (based on definitions given for building:structure) with roof:material=slate/tile for slate/tile roofs built in the conventional British way using timber joists and rafters with a slate or tile covering. Other examples include agricultural barns where the building supportive structure is steel framing (building/roof:structure=metal) and the walls and roof are of metal and fibre sheets (building:cladding=metal, roof:material=eternit).

It seems important to differentiate in detailed mapping of buildings as roof:material=roofing_felt/tar_paper/grass/gravel/etc. implies that the sole load-bearing component is a somewhat flimsy material when the actual material is merely a covering with no structural support qualities at all (i.e. it is not really the actual fabric of the roof). --John Grubb (talk) 04:53, 6 August 2019 (UTC)

If you want to add data on what's beneath the top-most layer, a key like roof:structure probably makes sense. I would like to keep roof:material defined as the roof's outer material (historically, this arose in part because it was originally invented for 3D rendering, but also because the structure beneath isn't necessarily visible for a mapper looking at the building from the outside). But adding a second tag alongside it ... why not? :) --Tordanik 19:46, 9 August 2019 (UTC)

Thanks for the support! I'm thinking that roof:material would remain to define the outer covering that can be seen. roof:structure would just be an extension for fuller information. If the structure was not known then it would be omitted and roof:material given on its own.

In the UK at least, it's general practice for domestic houses to have wooden roof structures to support the slates or tiles whilst industrial buildings, agricultural barns and the like are built with a building:structure and roof:structure of steel I-section beams with a metal sheet building:cladding and roof:material (in this regard it would seem that building:material could stand for the outer surface where building:structure is used but I didn't write the spec for that one, so...). It gets more difficult where old medieval, Tudor, Georgian, etc. era buildings come into play because they are often built from stone, cob (adobe) and other less advance materials and techniques so it's not always a given that "hidden" construction can accurately be assumed - or that outer finishes are what you might first think.

Another consideration is where cavity walls are not built with the same material for the inner and outer wall any more. I've watched a new estate of houses being built near me and the construction goes thus: poured concrete foundation, a couple of courses of cheap cement blocks, then a pre-cast concrete panel floor. The outer wall is then a couple of courses of nice brick where it will show and then back to cheap cement blocks. The inner wall is wood-framed and wood-panelled and dense foam sheets are placed in the cavity. The outer wall is then decoratively finished with rendering and the inner wall with plaster and paint. The roof is the conventional construction of wooden trusses, joists and battens with a covering of tar-based fibre material for water-proofing ("tar_paper" in OSM but more like roofing felt without the asphalt in reality) then the outer "roof:material" of slate or tile. Sometimes there is a non-functional (i.e. decorative) brick chimney.

How then to detailed-map that? Obviously, there's no need to create tags defining the entire component-by-component construction - that way lies madness! In the above example I would tag it roof:structure=wood_frame, roof:material=slate/tile with building:structure=cement_block, building:cladding=rendering and building:colour=white (assuming white render). The cement block part is the load-bearing component and thus the main "structure." In the roof the wood framing of the trusses is the main load-bearing part and is thus the "structure."

In building tagging where the structure/cladding combination couldn't be determined or it was obvious that the structure and outer finish were one and the same (e.g. an old cottage built from stone with no cavity) then I'd use building:material=stone and roof:material=thatch (for example) as there is no structure/cladding differentiation and the roof structure is unclear (although very likely to be wood_frame in this example). This potentially introduces an inconsistency of "mixed tagging" across the map where some buildings are tagged with structure and some with material to essentially describe the same component, and some buildings are not tagged with either due to "lazy" mapping or the item not being known to the mapper.

But I digress; back to roof:structure...

• Https://www.theplanner.co.uk/sites/default/files/Web Construction iStock 000000317725 Large.jpg

  Mixed build of cement block outer walls with a decorative brick footing and with conventional wood frame roof - here cement_block would be the building:structure, rendering the building:cladding and wood_frame the roof:structure, with roof:material being tile, slate or whatever is added when construction completes.

• Http://localdialogue.com/wp-content/uploads/2017/05/house-building2-57e946c11b4f7.jpg

  In this example building:material=brick, roof:structure=wood_frame and roof:material=slate. Alternatively, building:structure=brick and building:cladding=no, perhaps?

• Http://www.connecticutbuildingco.com/wp-content/uploads/CBC-another-possible-construction.jpg

  Here we see building:structure and roof:structure both taking wood_frame as the tag value.

• Https://www.businesslist.pk/img/pk/a/1438334120 12107.jpg

  An industrial building - building:structure, roof:structure, building:cladding and roof:material are all metal.

• Https://www.popeconstruction.com/wp-content/uploads/2013/04/metal-building-erection 1.jpg

  Another industrial building with a form of polymer sheet stretched over the frame - building:structure/roof:structure=metal, building:cladding/roof:material=plastic.

• Https://www.gh-construction.co.uk/wp-content/uploads/IMAG05051.jpg

  Here is a modern agricultural barn - building:structure/roof:structure=metal, building:cladding=wood (the predominant material), roof:material=metal. Possibly also a wall=no...?

• Https://www.teksupply.com/wcsstore/EngineeringServices/allbizunits/prodimages/zoom/1x/103739a.jpg

  Interesting one. Called a "hoop barn" - I do these as building=barn, building:levels=0, roof:levels=1, roof:shape=round, roof:structure=metal and roof:material=plastic/metal/eternit (depending on whether polymer sheet, metal or fibre-cement sheeting).

Okay, I give up! How do you link to an image in here...??!

Another variation example would be the small building - a garden shed, say - where the roof:structure is wood boards or sheets (e.g. plywood) so the roof material would be roofing_felt and the roof:structure would be wood rather than wood_frame, I should think - even though the wood sheets are attached to wooden battens and framing.

All good fun. Still, let's have a play with the idea and see where we can go with it.--John Grubb (talk) 05:15, 10 August 2019 (UTC)

Solar panels

I'd like to discuss the addition of "solar" as a roof material. There is already an existing tagging convention (mapping it as a generator with location=roof) documented as Tag:generator:source=solar#Rooftop Solar Panels which has far more uses. Part of the issue is that solar panels usually don't fully cover a roof: Parts around the edges, around chimneys, windows, etc tend to remain uncovered, and the northern side of the roof usually doesn't have any panels at all. --Tordanik 13:29, 22 March 2020 (UTC)

Perhaps it's meant for a solar roof, which really is the surface material? E.g. https://www.tesla.com/solarroof --Jeisenbe (talk) 01:27, 23 March 2020 (UTC)

The issue would then be that "solar" is not a "material". At least PV panel should be specified (cf generator:type=solar_photovoltaic_panel), and there are also solar thermal collectors. User:Tordanik's point of coverage still stands. It's a very relevant concern when there is a more detailed and established scheme. Perhaps only "true" solar roof entirely and tightly (lying flat along its surface) covered in solar energy collectors could be tagged as such in lieu of the actual roof material below (since solar panels may be installed and removed, see the under-structure/construct https://www.tesla.com/sites/default/files/solarroof/design/V3_Roof-Front_Exploded03.png); most critically power=generator shouldn't be left out. -- Kovposch (talk) 18:35, 23 March 2020 (UTC)

I would agree with the introduction of a material value for a roof covered with solar roof tiles (like Tesla's). However, that would be different from the currently documented "solar" value, seeing how the description and the image (a roof covered in roof tiles with separate solar panels on top) suggest traditionally installed panels. So I would like to remove that entry, but I'm open for the introduction of something like roof:material=solar_roof_tiles (or some other suitable value) that could be used in addition to generator tagging. -Tordanik 17:51, 31 March 2020 (UTC)

OK, I agree to remove it. I see it's been only used 10 times, and was added only in 2019, so that was inappropriate, it isn't common enough to be on this page. --Jeisenbe (talk) 11:20, 1 April 2020 (UTC)

Pergola-style roof

What is the right way to tag a roof that is made up of open-slats, like a pergola... Think of the photo in the "plants" material, but without the plants. If you stood under this roof, you'd get wet - but not mentioning it seems wrong as well. -- Djh11375 (talk) 17:40, 10 August 2020

That is a good question. How would you map this structure? I would think that building=roof is misleading for a pergola, because it does not provide protection from weather. Perhaps it is an amenity=shelter with shelter_type=pergola - used a couple of dozen times? https://taginfo.openstreetmap.org/tags/shelter_type=pergola - or perhaps a new tag like man_made=pergola would be better? --Jeisenbe (talk) 06:49, 12 August 2020 (UTC)

In my case, this pergola roof is part of a building - can a amenity=shelter with shelter_type=pergola and be a building_part=*? -- Djh11375 (talk)

If it's attached to the side of a house or other building, I would not map it as an amenity=shelter (unless perhaps it is in a public square or park and can be used by everyone). I'm also skeptical about mapping an open lattice structure as a building_part, so this would suggest the benefit of a new tag like man_made=pergola. --Jeisenbe (talk) 15:26, 12 August 2020 (UTC)

Classification guide

How one distinguishes eternit and asbestos (I even thought that it is the same thing)?

How asphalt is distinguished from tar_paper?

How one may distinguish corrugated plastic from corrugated metal?

How one may distinguish roof_tiles from plastic/metal sheets formed to look like roof tile?

Mateusz Konieczny (talk) 14:27, 11 January 2021 (UTC)

1) eternit vs asbestos: I think they are identical. Now I just realized this is very popular in Indonesia.

2) Asphalt vs tar_paper: there are "asphalt shingles" (most common roofing on houses in most of the USA) which look quite different from "tar paper". Though I'm not sure if that's how the tag is being used. There are also flat roofs where asphalt is poured out over the whole surface.

3) Corrugated metal is often shiny, galvanized, while plastic is fairly distinctive if it isn't painted, especially if it's translucent or transparent. But a painted plastic roof or metal roof can look quite similar.

4) Ceramic roof tiles are usually much thicker and rougher looking at the edges, and their coloration is less regular. But you have to survey this on the ground, not from aerial imagery in most cases. --Jeisenbe (talk) 06:16, 12 January 2021 (UTC)

1) Eternit is the trade name for asbestos-cement panels and is composed of 90% cement and 10% asbestos. So asbestos is only a component of eternit. Roofs are made of eternit so it's better to use this value. maro21 15:03, 3 May 2021 (UTC)

Today's and neutral (trade name free) term at least in Germany is Faserzement (de), fibre cement (en). --Chris2map (talk) 19:41, 3 May 2021 (UTC)

What roof material here?

What roof material can be given for such https://polska-org.pl/9699433,foto.html buildings?:) I'm sure this is common in modern skyscrapers. maro21 22:50, 3 March 2022 (UTC)