In every good residence provision should be made for preventing mice from going through the spaces between the studding and between the floor joists, and much may be done with a very little additional expense to prevent the rapid destruction of the building in case of fire.

Any material that will stop the progress of fire will also stop the passage of mice, but provisions may be made for stopping mice that . are not sufficient to stop fire.

When mice stops alone are to be provided, tin will be found the most convenient material, and it should be used so that it will be absolutely impossible for mice to ascend from the cellar into the outside walls or into the partitions, and the second story walls and partitions should be protected in the same way. If the building has an under floor the boards should be extended close against the outside sheathing of a wooden building and against the walls of a brick or stone building, and carefully cut around all studding. If there is no under floor the finished flooring (if laid before plastering) should be extended in the same way. The space between the outside studding and between the sheathing and plaster should then be covered with tin, turned up 1 inch against the studs and sheathing and tacked and every space, no matter how small, must be protected in this way or else solidly filled with brick and mortar or with mineral wool.

If the partitions are set on top of the flooring, a strip of tin 2 inches wider than the sole piece should be laid under it, as shown in Fig. 61.

If the studding rests on top of a partition cap below, a strip of tin may be laid between the studs on top of the under floor and turned up 1 inch against them. A better precaution, however, is to fill between the studding on top of the partition cap with five or six courses of salmon brick and mortar, as shown in Figs. 59 and 60, as this also forms an efficient fire stop. Where the chimneys are furred, or studded around, the space from the chimney to the back of the lathing should be closed with tin or brickwork. On brick walls that are furred by strapping, the easiest way to form a stop is to plaster between the strapping and flush with it for a distance of 10 or 12 inches just above and below the floor joists.

In localities where salmon bricks can be bought for $4 or $5 a thousand it will be about as cheap to fill the spaces between the studding with bricks and mortar as with tin. If asbestos sheathing is used as a lining between the flooring it may be fitted around the studding in place of the tin, but should be turned up against the sheathing and studding and tacked. When the owner is willing to go to the expense, it will be much better to fill the spaces between the studding, both in walls and partitions, the entire height with mineral wool, and thus gain the advantage of sound and heat insulation and slow combustion, as well as stopping mice.

If the architect undertakes to provide mice stops at all he should see that the work is done thoroughly, as mice can go through a very small hole, and if a few holes are left the work done will be almost useless.

Fire stops have been described in Section 71, but the work is generally done after the building is roofed in and while the carpenter is getting ready for the lathers. If the walls and partitions are fire stopped it is best to complete the work by laying a fireproof or incombustible lining between the flooring, as described in Section 138.

The work described in the last four sections will not add to the appearance of the building, and to see that it is thoroughly done will require close inspection, but when faithfully carried out it greatly enhances the value of the building as a place to live in, as well as adding to its security, and may possibly save a great loss from fire. It is in many points such as these, that are not apparent from a casual inspection, that architects' houses usually are, and always should be, superior to those of the speculative builder.