
1) Clapboard 2) Weatherboard
Found on
https://www.crosswordclues.com/clue/weatherboarding

• (n.) Boards adapted or intended for such use. • (n.) The covering or siding of a building, formed of boards lapping over one another, to exclude rain, snow, etc.
Found on
http://thinkexist.com/dictionary/meaning/weatherboarding/
Weath'er·board`ing noun (Architecture) (a) The covering or siding of a building, formed of boards lapping over one another, to exclude rain, snow, etc.
(b) Boards adapted or intended for such use.
Found on
http://www.encyclo.co.uk/webster/W/19

In architecture weatherboarding is a covering or siding of a building, formed of boards lapping over one another, to exclude rain, snow, etc.
Found on
http://www.probertencyclopaedia.com/browse/TW.HTM
No exact match found.