PLANK FLOORS. 



112k 



Plank Floors. As long as an excellent grade of timber was available and the concentrated 

 loads were not excessive, timber floors were quite satisfactory when properly constructed. Plank 

 floors should be of white oak, long leaf yellow pine or similar timber, laid transversely. Where 

 two layers of plank are used the lower layer is laid diagonally. Planks should be from 8 in. to 

 12 in. wide and not less than 3 in. thick. To carry modern auto trucks the plank should have a 

 minimum thickness in inches of three halves the spacing of the stringers in feet. Planks should 



Concrete per /in ft. of roadway* 6. 36 cubic yards. Reinforcement = 63. 5 pounds. 

 Pour this half of Floor first , Pour this half of floor last 





Construction Joint" i_ 



5ecTioriA-A SECT ion B-B 



Use this detail only when traFFic is to be maintained during construction. Otherwise 

 use detail given below. Other notes same as for detail shown below. 



&' Bridge and RpadwaylT-0 belweena/rds 6"^ 



*i^i-rj J-^. (A-~bars]l"<ti8"<t LOT ~t& $L 6 '} Jd---is-j 



J'\ fy-bars I 



1 -*k; 1 1 i-y..v.-.i 



: l'-3" \ Drain tF/oorbeam 



SECTIOttA-A 

 bw 



5KTIOHB-B 



<T\ ,, " c "'" 1 "";," -<^A 

 \3 1 6 fE^bars.'TopoFGurb I^Z-FlyTsrPaperJointoyer/^FIbms^ i 

 ,"""t' "7" ^LJ: i : '- L 



\ Stringer 



'J- Tar Paper Joint 

 ^"Searing P/dte 



5ECTion on &OF ROADWAY 



OcfiERAL HOTES SURFACE TREATrlEHT OF ROADWAY 



Concrete l:?:4mix, class CZ. 

 Reinforcements "round, medium open 

 hearth steel. H 



Drain-l"x2"tdperedoutonexh$Kle. 



Thoroughly clean surface and spread with coal tar heated 

 to tWorSWF.usinqratl&stjqallonspersq.yd. While tar is 

 still hot cover surface with? "of clean, coarse, sharp sand. 

 Tar must not be app/iedwhen concrete is damp. 



Concrete per /in. ft.of roadway = 0.36 cubic yards, 

 ffeinforcement per /in. ft. ofro3dway=57.8pour?ds. 



FIG. 8. REINFORCED CONCRETE FLOOR, MICHIGAN HIGHWAY COMMISSION. 



laid from J in. to \ in. apart so that water will not be retained, but will run through and will 

 give the planks an opportunity to dry out. Where more than one layer of planks is used a liberal 

 coating of coal tar to the upper side of the lower planks and to the lower side of the upper planks 

 will materially prolong the life of the floor. The timber in floors made of more than one layer of 

 planks should be creosoted. Each plank should be solidly spiked to each joist with spikes having 

 a length not less than twice the thickness of the plank, or 6-in. spikes for 3-in. plank and 8-in. 

 spikes for 4-in. plank. Where steel joists are used, spiking strips about 3 in. by 8 in. are bolted to 

 the tops of all joists, or spiking strips 4 in. by 6 in. are bolted to the sides of three lines of joists 





