diff --git a/README.rst b/README.rst
index c780064c8..190d74fb8 100644
--- a/README.rst
+++ b/README.rst
@@ -41,6 +41,20 @@ Install
 Instructions on how to add the OMERO.iviewer app to your installed OMERO.web apps
 can be found in the `OMERO.iviewer README <plugin/omero_iviewer/README.rst>`_.
 
+Settings
+========
+
+OMERO.iviewer limits the size of Z-projections to reduce load on the server.
+The limit is defined as the number of bytes of raw pixel data in a Z-stack and
+is equivalent to 1024 * 1024 * 256 bytes.
+For example, an 8-bit image (1 byte per pixel) of size 1024 * 1024 * 256 is
+equal to the default threshold. To double the limit, use::
+
+    $ omero config set omero.web.iviewer.max_projection_bytes 536870912
+
+NB: Z-projection is not supported for tiled images in OMERO
+(Images larger than 2000 * 2000 pixels per plane are tiled in iviewer).
+
 Supported URLs
 ==============
 
diff --git a/plugin/omero_iviewer/iviewer_settings.py b/plugin/omero_iviewer/iviewer_settings.py
index 1edbbd84b..e5e28bb87 100644
--- a/plugin/omero_iviewer/iviewer_settings.py
+++ b/plugin/omero_iviewer/iviewer_settings.py
@@ -25,6 +25,13 @@
 # load settings
 IVIEWER_SETTINGS_MAPPING = {
 
+    "omero.web.iviewer.max_projection_bytes":
+        ["MAX_PROJECTION_BYTES",
+         1024 * 1024 * 256,
+         int,
+         ("Maximum bytes of raw pixel data allowed for Z-projection. "
+          "Above this threshold, Z-projection is disabled")],
+
     "omero.web.iviewer.roi_page_size":
         ["ROI_PAGE_SIZE",
          500,
diff --git a/plugin/omero_iviewer/views.py b/plugin/omero_iviewer/views.py
index 40d337d81..9b2566928 100644
--- a/plugin/omero_iviewer/views.py
+++ b/plugin/omero_iviewer/views.py
@@ -47,6 +47,7 @@
 
 ROI_PAGE_SIZE = getattr(iviewer_settings, 'ROI_PAGE_SIZE')
 ROI_PAGE_SIZE = min(MAX_LIMIT, ROI_PAGE_SIZE)
+MAX_PROJECTION_BYTES = getattr(iviewer_settings, 'MAX_PROJECTION_BYTES')
 
 PROJECTIONS = {
     'normal': -1,
@@ -84,6 +85,7 @@ def index(request, iid=None, conn=None, **kwargs):
     if settings.FORCE_SCRIPT_NAME is not None:
         params['URI_PREFIX'] = settings.FORCE_SCRIPT_NAME
     params['ROI_PAGE_SIZE'] = ROI_PAGE_SIZE
+    params['MAX_PROJECTION_BYTES'] = MAX_PROJECTION_BYTES
 
     return render(
         request, 'omero_iviewer/index.html',
diff --git a/src/app/context.js b/src/app/context.js
index 97b9d49b3..fb9b1b3f9 100644
--- a/src/app/context.js
+++ b/src/app/context.js
@@ -439,6 +439,8 @@ export default class Context {
         this.interpolate = (interpolate === 'true');
         this.version = this.getInitialRequestParam(REQUEST_PARAMS.VERSION);
         this.roi_page_size = this.initParams[REQUEST_PARAMS.ROI_PAGE_SIZE] || 500;
+        this.max_projection_bytes = parseInt(this.initParams[REQUEST_PARAMS.MAX_PROJECTION_BYTES], 10)
+                                    || (1024 * 1024 * 256);
     }
 
     /**
diff --git a/src/controls/dimension-slider.js b/src/controls/dimension-slider.js
index 11eb81c80..4512d39fc 100644
--- a/src/controls/dimension-slider.js
+++ b/src/controls/dimension-slider.js
@@ -517,7 +517,13 @@ export default class DimensionSlider {
      */
     getZProjectionDisabled(handle, forwards) {
         let dims = this.image_config.image_info.dimensions;
-        return (handle !== null && forwards || (dims.max_x * dims.max_y) > UNTILED_RETRIEVAL_LIMIT);
+        let tiled = (dims.max_x * dims.max_y) > UNTILED_RETRIEVAL_LIMIT;
+        let bytes_per_pixel = Math.ceil(Math.log2(this.image_config.image_info.range[1]) / 8.0);
+        let size_c = this.image_config.image_info.channels.length;
+        let stack_size = dims.max_x * dims.max_y * dims.max_z * bytes_per_pixel * size_c;
+        let proj_limit = this.context.max_projection_bytes;
+
+        return (handle !== null && forwards || tiled || stack_size > proj_limit);
     }
 
     /**
diff --git a/src/index-dev.html b/src/index-dev.html
index 56b783eda..5ce904f29 100644
--- a/src/index-dev.html
+++ b/src/index-dev.html
@@ -33,8 +33,9 @@
         window.INITIAL_REQUEST_PARAMS = {
                 'VERSION': "DEV_SERVER",
                 'WEB_API_BASE': 'api/v0/',
-                'ROI_PAGE_SIZE': 500,
-                'IMAGES': "79833",   // "4420" // "73537",
+                'ROI_PAGE_SIZE': '500',
+                'MAX_PROJECTION_BYTES': "268435456", // 1024 * 1024 * 256
+                'IMAGES': "1252",   // "4420" // "73537",
                 // 'DATASET': "1",
                 //'WELL': "1"
         };
diff --git a/src/utils/constants.js b/src/utils/constants.js
index a7bcd46c1..a3c29cd1f 100644
--- a/src/utils/constants.js
+++ b/src/utils/constants.js
@@ -130,6 +130,7 @@ export const REQUEST_PARAMS = {
     WELL_ID: 'WELL',
     ZOOM: 'ZM',
     ROI_PAGE_SIZE: 'ROI_PAGE_SIZE',
+    MAX_PROJECTION_BYTES: 'MAX_PROJECTION_BYTES',
 }
 
 /**