Types of Stair Construction

Care must be taken, however, that the string lies well against the studding—even if it is necessary to put in thin blocking strips at each nailing place. Otherwise, there is danger of breaking the glue joint, where the treads and risers fit into the string.

There are several methods of joining the risers and treads. In Fig. 76 are shown the various methods of doing this. Some are con sidered better than others, but that is much a matter of opinion.

At A is shown how the risers come down upon the tread, and the tongue on the front side of the riser fits into a groove in the tread. If the fit is not good, there will be a crack in the front of the riser, which will become more apparent as the stair becomes older.

At G is another method. This is the com mon way when there is a rough string under the middle of the stair. At f is a similar arrangement except that the riser goes down behind the tread.

Fig. 76. Methods of Joining Risers and Treads.

All of these joints should be nailed or fast ened with wood screws.

At e and d, Fig. 76, are shown two ways of

joining the tread and riser at the nosing. They are practically the same, the one at d having the moulding set into the groove; while at e a tongue is cut on the front of the riser to fit into the groove in the tread. In d and e there is the danger of having the nosing break off, because the tread, unless made of a rather thick piece of wood, may crack over the groove.

In e and h are two more satisfactory meth ods. At c a tongue is cut on the back edge of the riser, and the groove in the tread is as a result farther back from the front of the tread than in e and d. A small moulding is put under the nosing, and there is little danger of the nosing breaking off. In g no groove is cut in the tread, so that the full strength of the tread is preserved. In this case, however, it is almost necessary to put a triangular strip, b, as shown, so as to fasten the tread and riser together. This strip may be put on with good results in all cases, as it will stiffen up the work consider ably.