diff --git a/src/main/resources/mappers/estimate/estimateMapper.xml b/src/main/resources/mappers/estimate/estimateMapper.xml
index a8e08298..3cced394 100644
--- a/src/main/resources/mappers/estimate/estimateMapper.xml
+++ b/src/main/resources/mappers/estimate/estimateMapper.xml
@@ -368,7 +368,7 @@
         /* sqlid : com.interplug.qcast.biz.estimate.selectEstimateRoofCertVolKw */
             <![CDATA[
         SELECT
-            CAST(SUM(F.VOL_KW) AS VARCHAR) AS CERT_VOL_KW
+            CAST(SUM(F.VOL_KW) AS NUMERIC(18, 3)) AS CERT_VOL_KW
         FROM (
                  SELECT
                      T.*,