Installation Guide
21
outside and inside corner posts
accessories installation
8"-12"
1/4" space at top of w
all
1/4"
1"
1"
Fig.1
Fig. 2
Fig.3
Step 1
A water-resistant material should be 
used to flash the inside and outside 
wall corners a minimum of 10˝ on 
each side before installation of the 
corner posts. A housewrap would be 
an adequate flashing (Fig. 1).
Step 2
Place the corner post in position, 
allowing a 1/4˝ gap between the top of 
the post and the eave or soffit 
(Fig. 2).
NOTE: If vinyl or aluminum soffit will be 
installed, either install prior to corner post 
installation or allow for soffit and accessory 
thickness when positioning the height of the 
corner.
Position a nail at the top of the upper 
slot on both sides of the corner post, 
leaving a 1/32˝ gap between the nail 
heads and the corner post nailing hem. 
The corner post hangs from these nails. 
The balance of the nailing should be in 
the center of the slot, 8˝ to 12˝ apart, 
again leaving 1/32˝ between the nail 
head and the corner post. This allows 
for the expansion and contraction to 
occur at the bottom. The corner post 
should extend 3/4˝ below the starter 
strip. Make sure the posts are vertically 
straight and square. 
Do not nail corner post tight.
Step 3
If more than one length of corner post 
is required, overlap the upper corner 
post over the lower corner post.
Splicing Outside 
Corner Post 
Remove 1˝ from the nail hem and 
receiving channel of the bottom end 
of the top piece. Position uncut top 
end of lower post under bottom edge 
of upper post allowing a 1/4˝ gap at 
the nail for expansion and contraction. 
(Fig. 3).










